Efficiency and security clindamycin vaginal cream (2%) were compared to oral metronidazole's for the treatment of 184 women with symptomatic bacterial vaginosis in a multicentric, randomized, double-blind, controlled study. The treatment was of 7 days duration, using placebo capsules for the clindamycin group and placebo cream for the metronidazole group. Patients were observed during a follow up (4-13 and 20-43 days after completion of therapy). Global results of this treatment indicated that clindamycin vaginal cream offers a similar efficiency than oral metronidazole. Improvement or total healing was 87% for clindamycin and 79% for metronidazole, with no significant differences (p > 0.22). No relapses were observed in the clindamycin group, and 7% in the metronidazole group. The clindamycin group had a failure rate of 3% compared to 15% in the oral metronidazole group. Both drugs were well tolerated. Side effects more frequently reported were vulvovaginal irritation and cervicitis/vaginitis. The only side effect that could have been classified as serious was a generalized rash in a patient receiving metronidazole. It was concluded that clindamycin vaginal cream (2%) is an efficient and secure alternative to oral metronidazole for the treatment of bacterial vaginosis being the elective therapy for pregnant women in their first gestational trimester.