Recent investigations have shown that plants with medicinal peculiarities as good alternative to anthelmintics for livestock. In this study, the anthelmintic effects of three medicinal herbs (Cinnamomum zeylanicum, Punica granatum flower and Capsicum annuum) were screened in vitro against the infective larvae of Parascaris equorum. The recovered larvae of the parasite were exposed to four concentrations (50, 75, 100 and 125 mg/mL) of the extracts and then they examined for the viability at 0, 10, 20, 30 and 40 minutes after the challenge. The results revealed that all the concentrations of each plant extract had anthelmintic effects on P. equorum larvae. Also, the statistics indicated that there were significant interactions between the concentration of the extracts and time of exposure on the number of viable larvae. In addition, C. annuum extract seemed to be a strong potency to kill larvae at all concentrations from the beginning of the experiment. These results confirmed that those herbal extracts possess good antiparasitic effects against infective larvae of P. equorum and thus could be considered in anthelminthic treatment strategies.