The bacterial epidemiology of bacterial vaginosis (BV) and the efficacy of vaginal or oral treatment of BV with clindamycin (CLDM) were investigated. The epidemiology of BV was investigated in 100 symptomatic women before CLDM therapy. Two groups consisting of 50 patients each with the diagnosis of symptomatic BV were treated with either oral administration of 450 mg CLDM three times daily or 2% CLDM phosphate in vaginal cream (self-made) 5 g once a day, for 7 days. There was no significant differences in efficacy among vaginal and oral therapies with CLDM. Vulvovaginal irritation occurred in 3 patients orally treated and in 1 patient vaginally treated. Gastrointestinal disturbances were observed in 4 orally treated patients. A slight abnormal elevation of the glutamine-oxaloacetic transaminase level was also found in 1 patient orally treated. Since there were no statistically significant differences in efficacy rates between vaginal and oral CLDM treatments, we favor vaginal treatment of BV, based on less adverse effects.