OBJECTIVE: To identify the factors associated with domestic violence against pregnant women. METHODS: Interviews were conducted with 1,379 pregnant women undergoing antenatal care in basic health care units of the Brazilian Health System, within the municipality of Campinas (Southeastern Brazil). A structured questionnaire on domestic violence, validated in Brazil, was applied between July 2004 and July 2006. The first and second interviews in a cohort study were analyzed. Descriptive and multiple logistic regression analysis of the data were conducted. RESULTS: Psychological violence was reported by 19.1% (n=263) of the total sample of pregnant women and physical/sexual violence was reported by 6.5% (n=89) of them. The factors associated to psychological violence were: adolescent intimate partner (p<0.019) and the pregnant woman had witnessed physical aggression before she was 15 years old (p<0.001). The factors associated to physical/sexual violence were: difficulties encountered by the pregnant woman in attending her antenatal appointments (p<0.014), intimate partner uses drugs (p<0.015) and does not work (p<0.048). The factors associated to psychological and physical/ sexual violence were: low level of education of the interviewee (p<0.013 and p<0.020, respectively), the pregnant woman being responsible for the family (p<0.001 and p=0.017, respectively) pregnant woman had suffered physical aggression during childhood (p<0.029 and p<0.038, respectively), presence of common mental disorder (p<0.001) and intimate partner consumes alcoholic beverage twice or more weekly. (p<0.001). CONCLUSIONS: A high prevalence of different categories of domestic violence by an intimate partner during pregnancy was found as well as different factors associated with them. Appropriate mechanisms are necessary, particularly in primary health care, to identify and deal with domestic violence during pregnancy.