Research on the determinants of affective polarization in Western democracies has blossomed in the past decade. But recent empirical and anecdotal evidence suggests that such phenomenon is not exclusive of advanced democracies as parties and candidates often appeal to voters on emotional or affective grounds, increasing levels of affective polarization in developing democracies as well. Yet, studies that analyze the causes of the aforementioned phenomenon outside developed democracies are scarce. This is surprising given that a number of scholars have already argued that elevated levels of affective polarization are a threat for the consolidation and survival of democracy. By focusing on Mexico, this paper contributes to a growing body of literature that analyzes the determinants of affective polarization outsied the U.S. and other Western democracies. Specifically, it tests three hypothesis that previous scholarship has put forth to explain affective polarization: (i) perceived ideological polarization, (ii) social sorting, and (iii) populist attitudes. Results indicate that perceived ideological polarization is a much stronger explanatory factor of affective polarization in Mexico than social sorting and populist attitudes.