diff --git a/.changeset/tender-cows-invite.md b/.changeset/tender-cows-invite.md
new file mode 100644
index 0000000000..d8179d1545
--- /dev/null
+++ b/.changeset/tender-cows-invite.md
@@ -0,0 +1,5 @@
+---
+"stylelint": patch
+---
+
+Fixed: `at-rule-property-required-list` performance
diff --git a/lib/rules/at-rule-property-required-list/index.js b/lib/rules/at-rule-property-required-list/index.js
index 1e88e0b16e..a093305a1b 100644
--- a/lib/rules/at-rule-property-required-list/index.js
+++ b/lib/rules/at-rule-property-required-list/index.js
@@ -1,6 +1,6 @@
 'use strict';
 
-const flattenArray = require('../../utils/flattenArray');
+const createMapWithSet = require('../../utils/createMapWithSet');
 const isStandardSyntaxAtRule = require('../../utils/isStandardSyntaxAtRule');
 const report = require('../../utils/report');
 const ruleMessages = require('../../utils/ruleMessages');
@@ -30,6 +30,11 @@ const rule = (primary) => {
 			return;
 		}
 
+		const propLists = createMapWithSet(primary);
+
+		/** @type {Set<string>} */
+		const currentPropList = new Set();
+
 		root.walkAtRules((atRule) => {
 			if (!isStandardSyntaxAtRule(atRule)) {
 				return;
@@ -37,32 +42,39 @@ const rule = (primary) => {
 
 			const { name, nodes } = atRule;
 			const atRuleName = name.toLowerCase();
-			const propList = flattenArray(primary[atRuleName]);
+			const propList = propLists.get(atRuleName);
 
 			if (!propList) {
 				return;
 			}
 
-			for (const property of propList) {
-				const propertyName = property.toLowerCase();
+			currentPropList.clear();
+
+			for (const node of nodes) {
+				if (!node || node.type !== 'decl') continue;
+
+				const propName = node.prop.toLowerCase();
+
+				if (!propList.has(propName)) continue;
 
-				const hasProperty = nodes.find(
-					(node) => node.type === 'decl' && node.prop.toLowerCase() === propertyName,
-				);
+				currentPropList.add(propName);
+			}
+
+			if (currentPropList.size === propList.size) {
+				return;
+			}
 
-				if (hasProperty) {
-					continue;
-				}
+			for (const requiredProp of propList) {
+				if (currentPropList.has(requiredProp)) continue;
 
 				report({
 					message: messages.expected,
-					messageArgs: [atRuleName, propertyName],
+					messageArgs: [atRuleName, requiredProp],
 					node: atRule,
 					word: `@${atRule.name}`,
 					result,
 					ruleName,
 				});
-				continue;
 			}
 		});
 	};
diff --git a/lib/utils/createMapWithSet.js b/lib/utils/createMapWithSet.js
new file mode 100644
index 0000000000..e6d2cb9c4e
--- /dev/null
+++ b/lib/utils/createMapWithSet.js
@@ -0,0 +1,25 @@
+'use strict';
+
+const flattenArray = require('./flattenArray');
+
+/**
+ * Create a map with unique sets of values from a record.
+ *
+ * @template T
+ * @param {Record<string, T | T[]>} record
+ * @returns {Map<string, Set<T>>}
+ */
+module.exports = function createMapWithSet(record) {
+	/** @type {Map<string, Set<T>>} */
+	const map = new Map();
+
+	for (const [key, value] of Object.entries(record)) {
+		const list = flattenArray(value);
+
+		if (!list) continue;
+
+		map.set(key, new Set(list));
+	}
+
+	return map;
+};