Background and objectives: Vaginitis is one of the most common diseases in women. Oak gall and ajwain have been used in traditional Persian medicine for treatment of vaginitis. The purpose of this study was to formulate a vaginal preparation containing oak gall and ajwain and evaluate its effectiveness on the recovery and recurrence of vaginitis. Methods: The present pilot study is a randomized, double-blind clinical trial performed on 24 women with mixed vaginitis, including bacterial vaginitis and trichomoniasis in a gynecology center. Subjects were divided into two groups receiving herbal vaginal tablets or metronidazole vaginal tablets for 7 days. The vaginal tablets were prepared using dried extract of oak gall and essential oil from ajwain by direct compression method. Clinical signs and laboratory tests were assessed after treatment. The symptoms were evaluated on day 10, and also 4 and 12 weeks after intervention. Results: There was a statistically significant difference in sexual function, and characteristics of secretions including amount, pH, odor, leukocyte count and parasite content in both groups of herbal (oak gall and ajwain) and metronidazole vaginal tablets before and after treatment (p