Ten variants of vaccines against trichophytosis were prepared. The vaccines were live and killed, nonadsorbed and adsorbed on aluminum hydroxide. The effectiveness of these vaccines was tested in laboratory conditions in 90 guinea pigs and 8 calves and in 110 farm calves. In the experiments with guinea pigs it was shown that it is possible to immunize them against the virulent strain T. verrucosum, where live vaccines proved to be the most effective, particularly those prepared from strain No 43 characterized by strong immunogenic properties. Vaccination of calves as that of guinea pigs appeared to be a procedure effectively protecting animals from experimental infection. In general, live vaccines used for immunization of calves caused full immunity of animals against a dose evoking infection after eight days since immunization. It is to be stressed that live vaccine prepared from the virulent strain No 43 evoked immune conditions after 4 weeks. Prophylactic vaccination of calves in nurseries in which trichophytosis has stationarily occurred for years gave positive results. Over eight months of observation a distinct decrease of the disease as well-as a weakened and shortened course of the disease were found.