The Monogenean parasite, Dactylogyrus sp., is being considered as one of the most dangerous pathogens in freshwater fish with a high infestation in common carp (Cyprinus carpio). The treatment of parasites including Monogeneans is an important part of fish health maintenance in the overall cycle of aquaculture. Novel applications of natural plant products to eradicate the parasites have taken high attention in aquaculture since they are reported to have less adverse impacts on the environment and fish in comparison to other chemical treatments. In the present study, in vitro antiparasitic effects of the ginger (Zingiber officinale) bulb and pomegranate (Punica granatum) peel against Dactylogyrus sp. were investigated by using in vitro tests. Individuals of the parasite were exposed to different concentrations of ginger (10, 50, 100, and 250 mg/ml) and pomegranate peel (50, 100, 250, and 500 mg/ml) for a specified period. In vitro cumulative mortality values reached 100% in 5 minutes after exposure to ginger at the concentration of 250 mg/ml in 9 minutes after exposure to 100 mg/ml and 50 mg/ml. Cumulative mortality was 58% in 9 minutes after exposure to ginger at the concentration of 10 mg/ml. In in vitro pomegranate tests, cumulative mortality values were assessed 100% in 3 minutes after exposure to pomegranate peel at the concentration of 500 mg/ml and in 6 minutes after exposure to 250 mg/ml and 100 mg/ml. Cumulative mortality was 66% in 6 minutes after exposure to pomegranate peel at the concentration of 50 mg/ml. In vitro results revealed that ginger and pomegranate peel solutions had antiparasitic effects on Dactylogyrus sp. to some degree, depending on solution concentration and exposure time. The efficacy of the ginger and pomegranate peel solutions against Monogeneans should be confirmed in fish through in vivo tests.