diff --git a/src/test/java/com/thealgorithms/slidingwindow/MinimumWindowSubstringTest.java b/src/test/java/com/thealgorithms/slidingwindow/MinimumWindowSubstringTest.java
new file mode 100644
index 000000000000..e003dfcc264a
--- /dev/null
+++ b/src/test/java/com/thealgorithms/slidingwindow/MinimumWindowSubstringTest.java
@@ -0,0 +1,23 @@
+package com.thealgorithms.slidingwindow;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * Unit tests for the MinimumWindowSubstring class.
+ *
+ * @author  (https://github.com/Chiefpatwal)
+ */
+public class MinimumWindowSubstringTest {
+
+    /**
+     * Tests for MinimumWindowSubstring.minWindow.
+     */
+    @Test
+    public void testMinimumWindowSubstring() {
+        assertEquals(4, MinimumWindowSubstring.minWindow("ADOBECODEBANC", "ABC")); // "BANC"
+        assertEquals(1, MinimumWindowSubstring.minWindow("a", "a")); // "a"
+        assertEquals(0, MinimumWindowSubstring.minWindow("a", "aa")); // ""
+    }
+}