Trichomonosis, caused by infection with a motile protozoan parasite called Trichomonas vaginalis, is the most common non-viral sexually transmitted disease worldwide. Since the 1960s, metronidazole has been used as a drug of choice. Considering increased resistance to anti-trichomonial drugs, alternative treatments are urgently needed. In this study, the standard strain of T. vaginalis was cultured in TYM medium. Curcumin and quercetin loaded with hyaluronic acid niosomes were prepared by the thin film hydration method. The mean vesicle size, polydispersity index, and zeta potential of each prepared formulation were characterized, and its anti-Trichomonas activity was assessed by concentrations of 0.01, 0.1, 1, 10 and 100 mg/ml. The cytotoxicity effects of the mentioned drugs were determined using a MTT assay on L929 fibroblast cell viability. The particle sizes of curcumin, quercetin, and curcumin-quercetin entrapped modified nano-niosomes were characterised as 243 ± 5.28, 223 ± 7.21 and 266 ± 4.81 nm. The results showed that quercetin and curcumin at a concentration of 100 mg/ml after 24 h had anti-T. vaginalis activity. However, curcumin at a concentration of 100 at time 3h with 97% growth inhibition had better performance than positive control (metronidazole). According to the results of the MTT assay, all drugs, even at the highest concentration (400 mg/ml), had no toxic effect on the fibroblast cell line. According to potent in vitro activity of curcumin and quercetin nanoniosomes against T. vaginalis in comparison with metronidazole, it can be concluded these compounds could be promising therapeutic candidates for trichomonosis in future.