Objective To investigate the vaginal irritation and skin sensitization associated with metronidazole vaginal gel, and to provide evidence for its clinical application. Methods An irritation test was carried out on rabbits for vaginal administration. After 7 days of continuous administration, possible vaginal irritation was observed and recorded. A skin allergy test was administered on guinea pig skin on days 0, 7, and 14. Sensitization was initiated on day 28 to observe guinea pig skin or systemic allergic reactions. Results The topical administration of metronidazole vaginal gel did not cause vaginal irritation or allergic reactions. Conclusions Metronidazole vaginal gel is safe for the treatment of bacterial vaginosis.