Abstract: The trichomonadicidal activity of tinidazole (Fasigyn) was evaluated by the ire vitro cultivation of Trichomonas vaginalis and Trichomonas hominis with different drug concentrations. The results showed that, after 48-hour incubation with tinidazole, the 100% lethal concentration was 20μg/ml. The trichomonadicidal effect of tinidazole was one titre lower than that of metronidazole. With regard to T. hominis, after 48-hour incubation with tinidazole, the 100% lethal concentration was 20μg/ml. In comparison with metronidazole, the trichomonadicidal effect of tinidazole was similar.