The effect of two daily applications of 1% 5-fluorouracil (5-FU) in 70% ethanol on penile condylomas was investigated in 65 men. Complete cures were obtained in 37% and marked regression in 42% of the patients. The most pronounced effect was seen on warts in the preputial cavity and on the adjacent foreskin, where the efficacy of 1% 5-FU in ethanol was comparable to that of 5% 5-FU cream. However, the pronounced side effects observed with use of the 5-FU cream were reduced to negligibility by use of an alcoholic vehicle for the drug. Patients who have therapeutically refractory condylomas in or near the preputial cavity should receive one or more courses of treatment with 1% 5-FU in ethanol. With regard to meatal warts, the effect of two daily applications of 5% 5-FU cream for two weeks was found to be therapeutically inferior as compared with results of previous studies in which the same treatment was extended for three to four weeks.