Trichomoniasis is a worldwide sexually transmitted disease caused by Trichomonas vaginalis. It inflicts severe complications to the human genitourinary system. The devastating negative effects and the emergence of resistance to common medication impose the search for safer and effective alternatives. This research aimed to investigate the effect of the Allium sativum, Nigella sativa crude extracts (NsCE) and the combination between their most effective doses with metronidazole. Methodology: Vaginal swabs were obtained from symptomatic patients, and cultured on Diamond's medium. Assessment of various concentrations of these herbs at different follow-up periods was done by counting the number of dead T. vaginalis trophozoites using the hemocytometer and trypan blue staining. Transmission electron microscope study was done. Results: NsCE 9mg/ml yielded the highest mean count of dead T.vaginalis trophozoites after 72hrs, compared with metronidazole. Combination of NsCE 9mg/ml and metronidazole 50µg/ml gave the best result. These results were confirmed by the ultrastructural changes observed in T. vaginalis trophozoites, signifying severe damage of nucleus and cytoplasm with large vacuolization and cell membrane defects. Conclusions: NsCE is a promising anti-Trichomonas especially its combination with metronidazole which showed a high synergistic effect