The life cycle of a new species of Clinostomidae, Clinostomum golvani, described in Guadeloupe (French West Indies). The first intermediate host is the snail vector of Schistosoma mansoni in this island, Biomphalaria glabrata, which can be sterilized by this parasite. Poecilia reticulata (guppy) serves as the second intermediate host. Adult worms were obtained under experimental conditions from Butorides virescens (the definitive host in nature), Nycticorax nycticorax and Ardea purpurea. The adult worm closely resembles Clinostomum complanatum but the larval stages (rediae and cercaria) show several differences. The chaetotaxic description of a cercaria of Clinostomidae is given for the first time.