Resveratrol, a natural phytoalexin found mainly in grapes, possesses antibacterial, antifungal, and antiviral properties. However, there is no information about its effects on helminths such as Trichinella sp. In the present study, we investigated the effects of resveratrol on the viability of Trichinella spiralis life stages in vitro. Adult forms, newborn larvae (NBL), and muscle larvae (ML) were incubated with resveratrol at concentrations varying from 12.5 to 200 mu g/ml. Resveratrol showed significant anthelmintic activity against NBL and adult forms of Trichinella, but not against ML. Our results suggest that resveratrol may be useful as a therapeutic agent to treat trichinellosis in early stages and warrant its further assessment in animal models of disease.