Women suffer from minor psychiatric disorders (MPM) more frequently than men. Most of the studies were conducted in England and in the United States and some reported the higher occurrence of MPM among women to be modified by marital status and others by sociodemographic variables. The present study intends to address this question in a developing country. Method: A population based case-control study was conducted in three important urban centers in Brazil. Two hundred seventy-six individuals diagnosed as new cases of MPM and 261 controls were selected to investigate the role of a set of sociodemographic variables in the association between gender and MPM using logistic regression models. Results: Univariate analysis showed that women were more likely than men to suffer from MPM (OR = 3.34; 2.27–4.91). After controlling for other sociodemographic variables, female gender was still positively associated with MPM, but not in a homogeneous way. A multiplicative interaction of gender with age group was found (LRT = 6.01; 2 df; p = 0.05) suggesting an increment in the magnitude of the association among those older than thirty years. Odds-ratios were 2.33 (1.19–4.55), 6.85 (2.86–16.41), and 7.47 (2.90–19.22) for age groups of fourteen to twenty-nine; thirty to forty-four; forty-five or more, respectively. There was no evidence of interaction of gender with marital status or other sociodemographic variables. Conclusions: The findings are consistent with the modification of the association between gender and MPM being mediated by social factors.