Abstract Introduction: Bacterial vaginosis (BV) is the most common cause of abnormal vaginal discharge in women during reproductive age. Diagnosis of bacterial vaginosis via clinical Amsel criteria remains widely competent. Objective: The aim of the study was to evaluate the effect of tinidazole tablets via Amsel criteria in Patients diagnosed Bacterial Vaginosis. Methods: In This randomized clinical duble-blind trial study, 110 non-pregnant women aged between 15-45 years old were referred to specialist clinic in Kangan city in 2012. Following their diagnosis confirmed bacterial vaginosis via Amsels criteria they divided in two groups for treatment. 52 woman received 2g tinidazole tablet one per day for 2 days and 48 women treated with 500mg metronidazole table twice per day for 7 days. Patients were evaluating two weeks following their treatment. For statistical analysis, descriptive statistics, t-test, McNamara, x2 and Fisher's exact test were performed. Results: After two week consumption of tinidazole tablet 19.2% of cases had abnormal vaginal discharge, 15.4% had positive whiff test, 21.2% had vaginal PH>4.5 and in 9.6% of cases, clue cell was more than 20% in vaginal discharge (p4.5 and in 8.3% of cases, clue cell was more than 20% in vaginal discharge (p<0.001). Conclusion: This study showed that oral tinidazole and metronidazole were efficient on all four Amsel criteria. As a result, these medicines still effective in the treatment of bacterial vaginosis.