diff --git a/Source/C/PSMatrix_c.h b/Source/C/PSMatrix_c.h
index b351b217..c07bd7a0 100644
--- a/Source/C/PSMatrix_c.h
+++ b/Source/C/PSMatrix_c.h
@@ -62,5 +62,6 @@ void ScaleMatrix_ps_wrp(int *ih_this, const double *constant);
 double MatrixNorm_ps_wrp(const int *ih_this);
 void MatrixTrace_ps_wrp(const int *ih_this, double *trace_val);
 int IsIdentity_ps_wrp(const int *ih_this);
+void MatrixDiagonalScale_ps_wrp(int *ih_mat, const int *ih_tlist);
 
 #endif
diff --git a/Source/CPlusPlus/PSMatrix.cc b/Source/CPlusPlus/PSMatrix.cc
index c2c296bd..d421c4df 100644
--- a/Source/CPlusPlus/PSMatrix.cc
+++ b/Source/CPlusPlus/PSMatrix.cc
@@ -217,6 +217,11 @@ void Matrix_ps::Scale(double constant) {
   ScaleMatrix_ps_wrp(ih_this, &constant);
 }
 
+//////////////////////////////////////////////////////////////////////////////
+void Matrix_ps::DiagonalScale(const TripletList_r &tlist) {
+  MatrixDiagonalScale_ps_wrp(ih_this, tlist.ih_this);
+}
+
 //////////////////////////////////////////////////////////////////////////////
 double Matrix_ps::Norm() const { return MatrixNorm_ps_wrp(ih_this); }
 
diff --git a/Source/CPlusPlus/PSMatrix.h b/Source/CPlusPlus/PSMatrix.h
index eb2bd2ab..d6e3bc90 100644
--- a/Source/CPlusPlus/PSMatrix.h
+++ b/Source/CPlusPlus/PSMatrix.h
@@ -160,13 +160,16 @@ class Matrix_ps {
   void Gemm(const Matrix_ps &matA, const Matrix_ps &matB,
             PMatrixMemoryPool &memory_pool, double alpha = 1.0,
             double beta = 0.0, double threshold = 0.0);
-  //! scale the matrix by a constatn.
+  //! scale the matrix by a constant.
   //! constant the value to scale by.
   void Scale(double constant);
   //! compute the norm of a matrix.
   double Norm() const;
   //! compute the trace of a matrix.
   double Trace() const;
+  //!\param tlist the triplet list.
+  //!\param threshold for flushing small values.
+  void DiagonalScale(const NTPoly::TripletList_r &tlist);
 
 public:
   //! Destructor.
diff --git a/Source/Fortran/PSMatrixAlgebraModule.F90 b/Source/Fortran/PSMatrixAlgebraModule.F90
index c2b13f86..6ecea2da 100644
--- a/Source/Fortran/PSMatrixAlgebraModule.F90
+++ b/Source/Fortran/PSMatrixAlgebraModule.F90
@@ -13,13 +13,16 @@ MODULE PSMatrixAlgebraModule
        & ConstructMatrixMemoryPool
   USE PSMatrixModule, ONLY : Matrix_ps, ConstructEmptyMatrix, CopyMatrix, &
        & DestructMatrix, ConvertMatrixToComplex, ConjugateMatrix, &
-       & MergeMatrixLocalBlocks, IsIdentity
+       & MergeMatrixLocalBlocks, IsIdentity, SplitMatrixToLocalBlocks
   USE SMatrixAlgebraModule, ONLY : MatrixMultiply, MatrixGrandSum, &
        & PairwiseMultiplyMatrix, IncrementMatrix, ScaleMatrix, &
-       & MatrixColumnNorm
+       & MatrixColumnNorm, MatrixDiagonalScale
   USE SMatrixModule, ONLY : Matrix_lsr, Matrix_lsc, DestructMatrix, CopyMatrix,&
        & TransposeMatrix, ComposeMatrixColumns, MatrixToTripletList
-  USE TripletListModule, ONLY : TripletList_r, TripletList_c
+  USE TripletListModule, ONLY : TripletList_r, TripletList_c, &
+       & ConstructTripletList, AppendToTripletList, DestructTripletList, &
+       & GetTripletAt
+  USE TripletModule, ONLY : Triplet_r, Triplet_c
   USE NTMPIModule
   IMPLICIT NONE
   PRIVATE
@@ -34,6 +37,7 @@ MODULE PSMatrixAlgebraModule
   PUBLIC :: ScaleMatrix
   PUBLIC :: MatrixTrace
   PUBLIC :: SimilarityTransform
+  PUBLIC :: MatrixDiagonalScale
 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
   INTERFACE MatrixSigma
      MODULE PROCEDURE MatrixSigma_ps
@@ -62,6 +66,10 @@ MODULE PSMatrixAlgebraModule
      MODULE PROCEDURE ScaleMatrix_psr
      MODULE PROCEDURE ScaleMatrix_psc
   END INTERFACE ScaleMatrix
+  INTERFACE MatrixDiagonalScale
+     MODULE PROCEDURE MatrixDiagonalScale_psr
+     MODULE PROCEDURE MatrixDiagonalScale_psc
+  END INTERFACE MatrixDiagonalScale
   INTERFACE MatrixTrace
      MODULE PROCEDURE MatrixTrace_psr
   END INTERFACE MatrixTrace
@@ -491,6 +499,34 @@ RECURSIVE SUBROUTINE ScaleMatrix_psc(this, constant)
     END IF
 
   END SUBROUTINE ScaleMatrix_psc
+!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+  !> Will scale a distributed sparse matrix by a constant.
+  SUBROUTINE MatrixDiagonalScale_psr(this, tlist)
+    !> Matrix to scale.
+    TYPE(Matrix_ps), INTENT(INOUT) :: this
+    !> A constant scale factor.
+    TYPE(TripletList_r), INTENT(IN) :: tlist
+    !! Local Data
+    TYPE(Matrix_lsr) :: lmat
+    TYPE(TripletList_r) :: filtered
+    TYPE(Triplet_r) :: trip
+
+#include "distributed_algebra_includes/ScaleDiagonal.f90"
+  END SUBROUTINE MatrixDiagonalScale_psr
+!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+  !> Will scale a distributed sparse matrix by a constant.
+  RECURSIVE SUBROUTINE MatrixDiagonalScale_psc(this, tlist)
+    !> Matrix to scale.
+    TYPE(Matrix_ps), INTENT(INOUT) :: this
+    !> A constant scale factor.
+    TYPE(TripletList_c), INTENT(IN) :: tlist
+    !! Local Data
+    TYPE(Matrix_lsc) :: lmat
+    TYPE(TripletList_c) :: filtered
+    TYPE(Triplet_c) :: trip
+
+#include "distributed_algebra_includes/ScaleDiagonal.f90"
+  END SUBROUTINE MatrixDiagonalScale_psc
 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
   !> Compute the trace of the matrix.
   SUBROUTINE MatrixTrace_psr(this, trace_value)
diff --git a/Source/Fortran/PSMatrixModule.F90 b/Source/Fortran/PSMatrixModule.F90
index 19812a28..423254e8 100644
--- a/Source/Fortran/PSMatrixModule.F90
+++ b/Source/Fortran/PSMatrixModule.F90
@@ -1443,7 +1443,7 @@ SUBROUTINE TransposeMatrix_psr(AMat, TransMat)
     !! Local Variables
     TYPE(TripletList_r) :: tlist
     TYPE(TripletList_r) :: new_list
-    TYPE(Triplet_r) :: trip, trip_t
+    TYPE(Triplet_r) :: trip
 
 #include "distributed_includes/TransposeMatrix.f90"
 
@@ -1458,7 +1458,7 @@ SUBROUTINE TransposeMatrix_psc(AMat, TransMat)
     !! Local Variables
     TYPE(TripletList_c) :: tlist
     TYPE(TripletList_c) :: new_list
-    TYPE(Triplet_c) :: trip, trip_t
+    TYPE(Triplet_c) :: trip
 
 #include "distributed_includes/TransposeMatrix.f90"
 
diff --git a/Source/Fortran/distributed_algebra_includes/ScaleDiagonal.f90 b/Source/Fortran/distributed_algebra_includes/ScaleDiagonal.f90
new file mode 100644
index 00000000..ee3b4db5
--- /dev/null
+++ b/Source/Fortran/distributed_algebra_includes/ScaleDiagonal.f90
@@ -0,0 +1,24 @@
+INTEGER :: II, row
+
+!! Merge to the local block
+CALL MergeMatrixLocalBlocks(this, lmat)
+
+!! Filter out the triplets that aren't stored locally
+CALL ConstructTripletList(filtered)
+DO II = 1, tlist%CurrentSize
+    CALL GetTripletAt(tlist, II, trip)
+    row = trip%index_row
+    IF (row .GE. this%start_row .AND. row .LT. this%end_row) THEN
+        trip%index_row = trip%index_row - this%start_row + 1
+        trip%index_column = trip%index_row
+        CALL AppendToTripletList(filtered, trip)
+    END IF
+END DO
+
+!! Scale
+CALL MatrixDiagonalScale(lmat, filtered)
+
+!! Split
+CALL SplitMatrixToLocalBlocks(this, lmat)
+CALL DestructMatrix(lmat)
+CALL DestructTripletList(filtered)
\ No newline at end of file
diff --git a/Source/Wrapper/PSMatrixAlgebraModule_wrp.F90 b/Source/Wrapper/PSMatrixAlgebraModule_wrp.F90
index 3fe86b2d..e333d6ac 100644
--- a/Source/Wrapper/PSMatrixAlgebraModule_wrp.F90
+++ b/Source/Wrapper/PSMatrixAlgebraModule_wrp.F90
@@ -20,6 +20,7 @@ MODULE PSMatrixAlgebraModule_wrp
   PUBLIC :: ScaleMatrix_ps_wrp
   PUBLIC :: MatrixNorm_ps_wrp
   PUBLIC :: MatrixTrace_ps_wrp
+  PUBLIC :: MatrixDiagonalScale_ps_wrp
 CONTAINS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
   !> Matrix B = alpha*Matrix A + Matrix B (AXPY)
   SUBROUTINE IncrementMatrix_ps_wrp(ih_matA, ih_matB, alpha_in,threshold_in) &
@@ -143,5 +144,19 @@ SUBROUTINE MatrixTrace_ps_wrp(ih_this, trace_value) &
     h_this = TRANSFER(ih_this,h_this)
     CALL MatrixTrace(h_this%DATA, trace_value)
   END SUBROUTINE MatrixTrace_ps_wrp
+!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+  !> Scale a matrix using a diagonal matrix (triplet list form).
+  SUBROUTINE MatrixDiagonalScale_ps_wrp(ih_mat, ih_tlist) &
+       & BIND(c,name="MatrixDiagonalScale_ps_wrp")
+    INTEGER(kind=c_int), INTENT(INOUT) :: ih_mat(SIZE_wrp)
+    INTEGER(kind=c_int), INTENT(IN) :: ih_tlist(SIZE_wrp)
+    TYPE(Matrix_ps_wrp) :: h_mat
+    TYPE(TripletList_r_wrp) :: h_tlist
+
+    h_mat = TRANSFER(ih_mat, h_mat)
+    h_tlist = TRANSFER(ih_tlist, h_tlist)
+
+    CALL MatrixDiagonalScale(h_mat%DATA, h_tlist%DATA)
+  END SUBROUTINE MatrixDiagonalScale_ps_wrp
 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 END MODULE PSMatrixAlgebraModule_wrp
diff --git a/UnitTests/test_psmatrixalgebra.py b/UnitTests/test_psmatrixalgebra.py
index 1d09c88b..f653aa6f 100644
--- a/UnitTests/test_psmatrixalgebra.py
+++ b/UnitTests/test_psmatrixalgebra.py
@@ -284,6 +284,29 @@ def test_reverse(self):
 
             self.check_result()
 
+    def test_scalediag(self):
+        '''Test routines to scale by a diagonal matrix.'''
+        from copy import deepcopy
+        for param in self.parameters:
+            matrix = param.create_matrix(complex=self.complex)
+            mmwrite(self.file1, matrix)
+            CheckMat = deepcopy(matrix)
+
+            tlist = self.TripletList()
+            for i in range(matrix.shape[1]):
+                t = self.Triplet()
+                t.index_column = i + 1
+                t.index_row = i + 1
+                t.point_value = i
+                tlist.Append(t)
+                CheckMat[:, i] *= i
+            ntmatrix = self.PSMatrix(self.file1)
+            ntmatrix.DiagonalScale(tlist)
+            ntmatrix.WriteToMatrixMarket(self.file2)
+
+            ResultMat = mmread(self.file2)
+            self._compare_mat(CheckMat, ResultMat)
+
 
 class TestPSMatrixAlgebra_r(TestPSMatrixAlgebra, unittest.TestCase):
     '''Special routines for real algebra'''
@@ -291,6 +314,8 @@ class TestPSMatrixAlgebra_r(TestPSMatrixAlgebra, unittest.TestCase):
     complex1 = False
     # Whether the second matrix is complex or not
     complex2 = False
+    TripletList = nt.TripletList_r
+    Triplet = nt.Triplet_r
 
     def test_dot(self):
         '''Test routines to add together matrices.'''
@@ -327,6 +352,8 @@ class TestPSMatrixAlgebra_c(TestPSMatrixAlgebra, unittest.TestCase):
     complex1 = True
     # Whether the second matrix is complex or not
     complex2 = True
+    TripletList = nt.TripletList_c
+    Triplet = nt.Triplet_c
 
     def test_dot(self):
         '''Test routines to add together matrices.'''
@@ -366,6 +393,8 @@ class TestPSMatrixAlgebra_rc(TestPSMatrixAlgebra, unittest.TestCase):
     complex1 = True
     # Whether the second matrix is complex or not
     complex2 = False
+    TripletList = nt.TripletList_r
+    Triplet = nt.Triplet_r
 
     def setUp(self):
         '''Set up a specific test.'''
@@ -381,6 +410,8 @@ class TestPSMatrixAlgebra_cr(TestPSMatrixAlgebra, unittest.TestCase):
     complex1 = False
     # Whether the second matrix is complex or not
     complex2 = True
+    TripletList = nt.TripletList_c
+    Triplet = nt.Triplet_c
 
     def setUp(self):
         '''Set up a specific test.'''