IThis article demonstrates that the phraseology plays a major role in creating Mexicanisms. It will present in the first place two lexicological works which take positions on Mexican Spanish’s status: “variation” or “language” in its own right. Then, it will demonstrate that most of mexicanisms are in a zone which includes the phraseology. It will show at the end that the mechanism of frozenness lies behind the Mexicanisms’ creation. The prototype Diccionario de contextos de uso de fraseologismos that is presented will allow to study the morphosyntactic, syntactico-semantic and pragmatic characteristics of the phraseological unities.