We explore urban mobility from a gendered perspective by analysing the mobility traces extracted from the Call Detail Records (CDRs) of a large cohort of about 400,000 anonymized mobile phone users in the greater metropolitan area of Santiago, Chile, over a period of 3 months. To investigate gender differences in mobility behavior, we analyze gender disaggregated mobility patterns of users by computing the number of unique locations visited by each user and their associated frequency of visits. We find that, even correcting for different calling behaviors of users, men’s trajectories display a higher entropy than women’s, suggesting the existence of a gender difference in the mobility of people in Santiago, with women moving less than men and distributing their time less equally among fewer locations. By computing the ratio of mobility entropies (women over men) and mapping its values to the users’ inferred location of residence, we find that gender difference in mobility varies across the comunas of Santiago. More specifically, the gender gap in mobility, measured by the entropy ratio, is correlated to a number of socio-economic indices available from census. Among them, a lower average income of a comuna (see Fig. 1), a higher presence of families with dependant minors and a lower number of registered vehicles, appear to be the strongest predictors of an increasing gender gap in mobility.