Before the beginning of radium therapy a vaginal yeast contamination of 9,7% was found of 113 patients with different genital carcinomas. However, the incidence of vaginal yeast contamination increased suddenly to 30,9% under the contac irradiation therapy with radium. The radiation effect of radium is not sufficient for a "selfsterilisation" of the radium-carrier in the case of yeast contamination. Therefore, a chemic desinfection of the radium-carriers is principly necessary. The significance of radium therapy with respect to vaginal yeast contamination is discussed and the recommendation is made that routine mycological supervision be carried out on all patients with gynaecological carcinomas and appropriate antimycotic therapy initiated where necessary.