To analyse risk factors for bacterial vaginosis (BV). We conducted a case-control study on risk factors for BV, in several first-level gynecological centers in Italy. Cases were women aged 18-70 years with confirmed diagnosis of BV (using test for proline iminopeptidase (PIP) activity). Control were the first patients observed in the same center without any symptom suggesting vaginal infection, and a negative PIP activity test. A total of 476 cases and 450 controls entered the study. The number of sexual partners in the month before interview, but not the number of intercourses, was associated with an increased risk of BV. The risk of BV with vaginal douching or tight jeans/trousers once or more a week was 2.0 (95% CI 1.0-3.9) and 1.5 (95% CI 1.0-2.2), respectively, compared to never users. The findings are consistent with previous data and suggest that daily habits play an important role in risk of BV.