diff --git a/arrays_and_strings/matrix-sum-diagonals.py b/arrays_and_strings/matrix-sum-diagonals.py
new file mode 100644
index 0000000..6999fa4
--- /dev/null
+++ b/arrays_and_strings/matrix-sum-diagonals.py
@@ -0,0 +1,31 @@
+#!/bin/python3
+# Given a square matrix, calculate the absolute difference between the sums of its diagonals.
+
+import math
+import os
+import random
+import re
+import sys
+
+def diagonal_difference(arr):
+
+    diag_1 = 0
+    diag_2 = 0
+    
+    i, j = 0, len(arr) - 1
+    
+    while i < len(arr) and j >= 0:
+        
+        diag_1 += arr[i][i]
+        diag_2 += arr[i][j]
+        i += 1
+        j -= 1
+        
+    return diag_1, diag_2, abs(diag_1 - diag_2)
+            
+            
+
+if __name__ == '__main__':
+    
+    arr = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
+    print(diagonal_difference(arr))