Sexually transmitted diseases (STDs) have been a subject of discussion both among scientists and in the mass media, especially because of their association with the human immunodeficiency virus (HIV). We studied the adoption of specific protective behaviors for the prevention of STDs among women, as well as the associations between these behaviors and socioeconomic and demographic variables. This was a descriptive study based on secondary data from a previous study carried out in Campinas, São Paulo State, Brazil. A total of 635 women were selected using the social network ("snowball") technique. Subjects were classified into four groups: adolescents and adults of upper middle and lower socioeconomic status, respectively. Condoms were the STD prevention method most frequently mentioned by interviewees. A negative association was observed between having a steady partner and condom use in all the groups. The main reason mentioned for not using condoms was "having a single partner and trusting him". Among adolescents, a positive association was observed between schooling above the 8th grade and condom use, and a negative association was observed between age and condom use. Among adults, only condom use in general was also positively associated with socioeconomic status.