A cross-sectional study was conducted with 936 family caregivers of users of Psychosocial Care Centers (CAPS) with the aim of describing the prevalence of minor psychiatric disorders and the association with socio-demographic variables, self-reported overload, and stressful events. Minor psychiatric disorder was identified with the Self-Reporting Questionnaire (SRQ-20), using as case definition a cutoff of eight or more positive answers for women and six or more for men. Bivariate and multivariate analyses were conducted by Poisson regression. Prevalence of minor psychiatric disorders was 49% (95%CI: 46%-52%). In the adjusted analysis, higher prevalence was observed in families with less schooling, health problems, more stressful life events, retirees, and single caregivers who reported overload. The results indicate a high prevalence of minor psychiatric disorders, besides identifying some associations. Such information provides important support for planning mental health services and primary care.