diff --git a/coding_interviews/leetcode/medium/maximum-sum-of-an-hourglass/maximum-sum-of-an-hourglass.js b/coding_interviews/leetcode/medium/maximum-sum-of-an-hourglass/maximum-sum-of-an-hourglass.js
new file mode 100644
index 0000000..df09e47
--- /dev/null
+++ b/coding_interviews/leetcode/medium/maximum-sum-of-an-hourglass/maximum-sum-of-an-hourglass.js
@@ -0,0 +1,28 @@
+// https://leetcode.com/problems/maximum-sum-of-an-hourglass
+
+function maxRowSum(grid, row, col) {
+  return (
+    grid[row][col] +
+    grid[row][col + 1] +
+    grid[row][col + 2] +
+    grid[row + 1][col + 1] +
+    grid[row + 2][col] +
+    grid[row + 2][col + 1] +
+    grid[row + 2][col + 2]
+  );
+}
+
+function maxSum(grid) {
+  let maxSumOfAnHourglass = 0;
+
+  for (let row = 0; row + 2 < grid.length; row++) {
+    for (let col = 0; col + 2 < grid[row].length; col++) {
+      maxSumOfAnHourglass = Math.max(
+        maxSumOfAnHourglass,
+        maxRowSum(grid, row, col)
+      );
+    }
+  }
+
+  return maxSumOfAnHourglass;
+}