There are no universally successful guidelines for treatment of metronidazole-resistant vaginal trichomoniasis. That is distressing for patients and frustrating for physicians. Zinc sulfate is generally known as antimicrobial chemical defense in human. Here we report our experience that zinc sulfate douche has a therapeutic effect on metronidazole-resistant vaginal trichomoniasis. In our report, a retrospective case review identified 8 cases of metronidazole-resistant trichomonas between 2005 and 2013. In the absence of resistance testing, resistance was defined clinically (Metronidazole-resistance is defined clinically as a failure to cure infection after 2 consecutive course of treatment). They have received 1% zinc douche with or without oral tinidazole for 14 days to 28 days. All of our patients experienced clinical improvement, lasting for days or weeks, with a negative vaginal wet smear. At their last review, seven patients had remained symptom free with normal clinical examination results and negative wet mount and only one patient had recurred. Because pregnancy, she didn`t have sufficient therapeutic period. Two of them were treated with only 1% zinc sulfate douche and others were treated with combination of zinc sulfate douche and tinidazole. Although the exact role of zinc sulfate douche is uncertain, therapeutic effect of zinc is clearly achieved in our patients. This study has several limitations. Our investigation was a retrospective medical record review rather than a prospective, in vitro susceptibility tests to metronidazole or tinidazole were obtained in no patients. But we believe that zinc sulfate therapy merits further independent evaluation.