diff --git a/csharp/1343-number-of-sub-arraysofSize-k-and-average-greaterthanor-equal-to-threshold.cs b/csharp/1343-number-of-sub-arraysofSize-k-and-average-greaterthanor-equal-to-threshold.cs
new file mode 100644
index 000000000..ee222b866
--- /dev/null
+++ b/csharp/1343-number-of-sub-arraysofSize-k-and-average-greaterthanor-equal-to-threshold.cs
@@ -0,0 +1,44 @@
+/*
+
+Approach:
+1. We will initialize i, j, c, res, and sum to 0.
+2. We will calculate the sum of the first k elements and check if the average is greater than or equal to the threshold.
+3. We will increment the result if the average is greater than or equal to the threshold.
+4. We will iterate through the array and calculate the sum of the next k elements.
+5. We will check if the average is greater than or equal to the threshold and increment the result accordingly.
+6. We will return the result.
+
+Time Complexity: O(n)
+Space Complexity: O(1)
+
+*/
+public class Solution {
+    public int NumOfSubarrays(int[] arr, int k, int threshold) {
+        int i ,j, c, res, sum;                          // Initialize i, j, c, res, and sum to 0.
+        i = c = sum = res = 0;                          // Initialize i, c, sum, and res to 0.
+        j = i + k - 1;                                  // Initialize j to i + k - 1.
+
+        while (c <= j) {                                // Calculate the sum of the first k elements.
+            sum = sum + arr[c];                         // Add the element at index c to the sum.
+            c++;                                        // Increment c.
+        }
+
+        res = (sum/k) >= threshold ? 1 : 0;             // Check if the average is greater than or equal to the threshold and increment the result accordingly.
+
+        while ( j < arr.Length) {                       // Iterate through the array and calculate the sum of the next k elements.
+            sum = sum - arr[i++];                       // Subtract the element at index i from the sum and increment i.
+            j++;                                        // Increment j.
+            if(j < arr.Length) {                        // Check if j is less than the length of the array.
+                sum = sum + arr[j];                     // Add the element at index j to the sum.
+            }
+            else {
+                break;                                  // Break the loop if j is equal to or greater than the length of the array.
+            }
+            if((sum/k) >= threshold) {                  // Check if the average is greater than or equal to the threshold.
+                res++;                                  // Increment the result.
+            }
+        }
+
+        return res;                                     // Return the result.
+    }
+}