Coriandrum sativum has been used in Iranian traditional medicine as an anti-inflammatory, antioxidant, antibacterial, and antifungal agent. The purpose of this study was to evaluate the chemical composition and anti-parasitic property of essential oil of C. sativum leaf on trophozoite of Trichomonas vaginalis. C. sativum was collected from Kermanshah city and essential oil was prepared by the Clevenger device. The essential oil was analyzed by GC/MS. Trophozoite of T. vaginalis was cultured in vitro in CPLM medium and the effect of the essential oil on the survival of T. vaginalis trophozoite was measured by Neobar slide. This study indicated that Linalool (71.2%) was the most constituent found in C. sativum essential oil. Also, the results of anti-parasitic tests demonstrated the concentrations of 0.5, 0.25, 0.125, 0.062, 0.031, 0.015, 0.007, 0.003, and 0.001 g/ml in essential oil and 0.25 g/ml in metronidazole could destroy of T. vaginalis trophozoite completely after 420 minutes incubation. The best results were observed at 0.5 and 0.25 g/ml concentrations of essential oil, because these concentrations were able to destroy trophozoite in 90 minutes. Also, 0.001 g/ml concentration of essential oil had the lower anti-parasitic effect than all concentrations against T. vaginalis trophozoite. The trophozoite survived at DMSO after 600 minutes. MIC and MLC of C. sativum essential oil were 0.015 and 0.031 g/ml concentrations, respectively. In our study, the essential oil of C. sativum leaf in several concentrations destroyed T. vaginalis trophozoite. It appears that C. sativum can be used for the treatment of some T. vaginalis infections as an antibiotic.