This method has been developed for the routine observation of the different forms of Trichomonas vaginalis in axenic culture with a low rate of cell loss. This rapid dyeing process is especially suitable for the examination of the ratio between the flagellated and round forms of the parasite. As a result of this staining one can not see fine cell details but can firmly distinguish between flagellated forms and multi-nucleated, multi-flagellated forms (i.e. dividing cells forms).