Women in Benue State have for years had the highest HIV rate in the country, but because the sentinel surveys are anonymized and unlinked, not much is known about the socio-demographic, behavioural and other risk factors that predispose these women to the disease. The HIV/AIDS epidemic in Nigeria does not appear to be a single epidemic but rather multiple epidemics of varying magnitude and trends. This cross-sectional study was therefore carried out to identify the risk factors for HIV/AIDS among these women. A total of 404 consecutive consenting mothers enrolled at the booking clinic were followed up until delivery of their babies. They were interviewed using a semi-structured questionnaire and tested for HIV infection using an ELISA-based kit after obtaining informed consent. Mean age of the mothers was 26±6·1 years, 94·8% were married while 50·5% had at least secondary level education. Sixty-one (15·1%) mothers were HIV positive with mothers aged 15–24 years being responsible for 50·8% of all infection. Following bivariate analysis, being single, having a partner with low level of formal education, living in a rural location, being in a polygamous/multiple partner union, being a higher order polygamous wife, being married more than once and reporting a history of a sexually transmitted infection were significantly associated with HIV infection. Monogamous women who lived apart from their partners and women who had ever had blood transfusion were also more likely to be HIV positive. Following multivariate logistic regression, a young age of 15–24 years (multivariate OR=3·3, 95% CI=1·2–8·4, p=0·02); ever had other STIs (OR=1·6, 95% CI 1·1–2·3, p=0·009); no formal maternal education (OR=0·6, 95% CI 0·4–0·9, p=0·021) and having one lifetime sexual partner (OR=0·4, 95% CI 0·3–0·5, p<0·00001) were significantly associated with HIV infection in the study population. Appropriate interventions must be directed at young people and should include STI control and abstinence education. Blood safety must be ensured as well as a general improvement in the level of formal and health education in this community.