diff --git a/icu4c/source/i18n/plurrule.cpp b/icu4c/source/i18n/plurrule.cpp
index 839d14147cc2..b8ad0b2736f0 100644
--- a/icu4c/source/i18n/plurrule.cpp
+++ b/icu4c/source/i18n/plurrule.cpp
@@ -656,6 +656,11 @@ PluralRuleParser::parse(const UnicodeString& ruleData, PluralRules *prules, UErr
         case tEqual:
             {
                 U_ASSERT(curAndConstraint != nullptr);
+                if (curAndConstraint->rangeList != nullptr) {
+                    // Already get a '='.
+                    status = U_UNEXPECTED_TOKEN;
+                    break;
+                }
                 LocalPointer<UVector32> newRangeList(new UVector32(status), status);
                 if (U_FAILURE(status)) {
                     break;
diff --git a/icu4c/source/test/intltest/plurults.cpp b/icu4c/source/test/intltest/plurults.cpp
index 664b27f4bb73..0771baa75860 100644
--- a/icu4c/source/test/intltest/plurults.cpp
+++ b/icu4c/source/test/intltest/plurults.cpp
@@ -69,6 +69,7 @@ void PluralRulesTest::runIndexedTest( int32_t index, UBool exec, const char* &na
     TESTCASE_AUTO(testFixedDecimal);
     TESTCASE_AUTO(testSelectTrailingZeros);
     TESTCASE_AUTO(testLocaleExtension);
+    TESTCASE_AUTO(testDoubleEqualSign);
     TESTCASE_AUTO_END;
 }
 
@@ -1638,6 +1639,16 @@ void PluralRulesTest::compareLocaleResults(const char* loc1, const char* loc2, c
     }
 }
 
+void PluralRulesTest::testDoubleEqualSign() {
+    IcuTestErrorCode errorCode(*this, "testDoubleEqualSign");
+
+    // ICU-22626
+    // Two '=' in the rul should not leak.
+    LocalPointer<PluralRules> rules(
+        PluralRules::createRules(u"e:c=2=", errorCode), errorCode);
+    errorCode.expectErrorAndReset(U_UNEXPECTED_TOKEN);
+}
+
 void PluralRulesTest::testLocaleExtension() {
     IcuTestErrorCode errorCode(*this, "testLocaleExtension");
     LocalPointer<PluralRules> rules(PluralRules::forLocale("pt@calendar=gregorian", errorCode));
diff --git a/icu4c/source/test/intltest/plurults.h b/icu4c/source/test/intltest/plurults.h
index 98ea9574bea7..e245a44590b8 100644
--- a/icu4c/source/test/intltest/plurults.h
+++ b/icu4c/source/test/intltest/plurults.h
@@ -50,6 +50,7 @@ class PluralRulesTest : public IntlTest {
     void testFixedDecimal();
     void testSelectTrailingZeros();
     void testLocaleExtension();
+    void testDoubleEqualSign();
 
     void assertRuleValue(const UnicodeString& rule, double expected);
     void assertRuleKeyValue(const UnicodeString& rule, const UnicodeString& key,