Bacterial vaginosis is common and frequently recurrent, imposing substantial burdens on women's health. A new trial conducted in Australia has for the first time shown decreased BV recurrence in women whose male partners were treated with BV-directed oral plus topical antibiotics, but whether this intervention will be equally efficacious in the United States (US) is unclear; a non-systemic antibiotic regimen would be preferred. We propose a three-arm, parallel-group, open-label (investigator-masked), Phase III randomized controlled trial of male partner therapy to prevent BV recurrence in which women with symptomatic BV receive standard BV therapy and male partners are randomized to no treatment, topical clindamycin alone, or oral metronidazole plus topical clindamycin; if successful this could change US clinical practice and inform national guidelines to improve reproductive and obstetric health.