A therapeutic trial of 5% 5-Fluoro-uracil in cream form was conducted in 40 men with condylomata acuminata unresponsive to other therapeutic measures. Sixty per cent of the condylomata on the genital and/or anal mucosa showed complete regression. The most promising results were recorded in the cases of condylomata affecting the urinary meatus. These lesions disappeared in 13 of 14 cases after an average of 3 weeks' treatment with subjectively few side effects. With regard to this type of condylomata it may be said that a great therapeutical advance has been achieved. The treatment of other condylomata involving the genital or anal mucosa often causes intolerable discomfort to the patients. The method should in these cases therefore be attempted only when the lesions prove to be refractory to other methods of treatment. In its present form the application of 5-FU cream is difficult to confine solely to the condylomata itself. The cream appears to have little or no effect on condylomata at sites other than the mucosa.