Trichomonas vaginalis could not be isolated from the water of a highly frequented swimming pool of the City of Zurich. The protozoon T. vaginalis may show a slight degree of motility; even after 20 minutes exposure to the chlorinated water of a swimming pool; but it looses its infectivity within seconds after exposure to water of the swimming pool. It is not yet known how trichomonads are able to survive in the secretions of the vagina and on contaminated objects (fomites) in dressing rooms.