In recent decades, Mexico has introduced increasingly strict electoral rules regarding the gender electoral regime, while the descriptive representation of women has been increasing. This article analyzes empirically the relationship between the strength of the gender electoral regime and the descriptive representation of women in local congresses of the 32 states, expanding the longitudinal analysis based on the data of most local legislatures between 1987 and 2019. It aims to identify whether the gender electoral regime of each state has been strengthened (diachronic comparison) and if there is a positive relationship between the strength of the gender electoral regime (synchronous comparison) and the proportion of female legislators in each local congress. The results of this research suggest that the stronger the gender electoral regime, the greater the predicted proportion of women elected by the principles of relative majority and proportional representation, even after controlling for other political and socioeconomic factors. The results also illustrate that the effect of the gender electoral regime index is not homogeneous among sub-national entities.