This contribution aims to analyse the language contact phenomena between Yucatec Maya and Spanish, focusing specifically on the case of pronominals. This empirical study takes place in the village of Xocén in Yucatán, Mexico where most locals speak Maya while Spanish is the official language also spoken by many (bilingual) locals. The use of pronominals in Maya differs from Spanish in terms of morphology, functions, case assignment, syntactic conditions, and discourse conditions. I apply the interface hypothesis developed by Sorace (2011) which expects bilinguals to show optionality in the use of pronominals that require specific syntactic and discourse conditions (interface), and the contact-induced language change hypothesis developed by Heine and Kuteva (2003) which expects the formation of the pronominals in Maya to be influenced by Spanish. In a case study with three monolingual Mayan speakers and six bilingual Mayan-Spanish speakers, I collected freely produced speech data in Maya focusing on the use of pronominals and analysed the different functions these pronominals fulfil. The results show that bilinguals do display optionality regarding certain pronominals that exist at interfaces and that no influence of Spanish can be found in the Mayan pronominal system. Therefore, Maya-Spanish bilingualism can be better characterised by Sorace’s interface hypothesis (2011) than by contact-induced grammaticalisation (Heine and Kuteva 2003).