To compare efficacy and tolerability between different regimens of rifaximin vaginal tablets and a placebo for treatment of bacterial vaginosis. In a prospective study carried out at 13 sites in 3 European countries between August 2009 and October 2010, White, non-pregnant, premenopausal women with bacterial vaginosis were randomly assigned to receive rifaximin at 100mg for 5 days (100mg/5 days), 25mg/5 days, or 100mg/2 days, or placebo. Women were assessed at 7-10 and 28-35 days. Diagnosis and cure were based on Amsel criteria and Nugent score. Fisher exact test was used to compare cure rates. Among 114 women recruited, 103 were evaluable for drug efficacy. Therapeutic cure rate at first follow-up was higher in the rifaximin 25mg/5 days (48%, P=0.04), 100mg/2 days (36.0%), and 100mg/5 days (25.9%) groups than in the placebo group (19.0%). At second follow-up, therapeutic cure rate was 28.0%, 14.8%, and 4.0% in the respective groups versus 7.7% in the placebo group. No difference in adverse events was observed. Rifaximin at 25mg/5 days showed better therapeutic cure rates and maintenance of therapeutic cure after 1 month versus placebo. All treatment regimens were well tolerated. EudraCT number: 2009-011826-32.