diff --git a/leetcode/solutions/0020.ValidParentheses/isValid.ts b/leetcode/solutions/0020.ValidParentheses/isValid.ts
new file mode 100644
index 0000000..44360ea
--- /dev/null
+++ b/leetcode/solutions/0020.ValidParentheses/isValid.ts
@@ -0,0 +1,23 @@
+/**
+ * @param {string} s
+ * @return {boolean}
+ */
+export default function isValid(
+  s: string
+): boolean {
+  if (s.length % 2 !== 0) {
+    return false;
+  }
+
+  const closerMap = new Map([["{", "}"], ["(", ")"], ["[", "]"]]);
+  const openerSet = new Set(closerMap.keys());
+  const closerStack: string[] = [];
+  for (let i = 0; i < s.length; i++) {
+    if (openerSet.has(s[i])) {
+      closerStack.push(closerMap.get(s[i])!);
+    } else if (closerStack.pop() !== s[i]) {
+      return false;
+    }
+  }
+  return closerStack.length === 0;
+}
diff --git a/leetcode/solutions/0020.ValidParentheses/isValid_test.ts b/leetcode/solutions/0020.ValidParentheses/isValid_test.ts
new file mode 100644
index 0000000..1107fed
--- /dev/null
+++ b/leetcode/solutions/0020.ValidParentheses/isValid_test.ts
@@ -0,0 +1,11 @@
+import { test } from "https://deno.land/std/testing/mod.ts";
+import { assertEquals } from "https://deno.land/std/testing/asserts.ts";
+import isValid from "./isValid.ts";
+
+test("0020. Valid Parentheses", () => {
+  assertEquals(isValid("()"), true);
+  assertEquals(isValid("()[]{}"), true);
+  assertEquals(isValid("(]"), false);
+  assertEquals(isValid("([)]"), false);
+  assertEquals(isValid("{[]}"), true);
+});