Four hundred and fifty patients were enrolled into a randomised clinical trial in a public sexually transmitted diseases clinic to evaluate the efficacy of podophyllin, cryotherapy, and electrodesiccation for treatment of external genital warts. Complete clearance of warts was observed in 41%, 79%, and 94% of patients who received up to six weekly treatments of podophyllin, cryotherapy, and electrodesiccation, respectively. Relapses occurred in 25% of all patients, yielding 3 month clearance rates of 17%, 55%, and 71% for podophyllin, cryotherapy, and electrodesiccation, respectively. Wart volume and duration did not influence treatment outcome. Response to therapy was greater in women than in men, and did not differ by treatment modality. Electrodesiccation and cryotherapy were more effective than podophyllin for the treatment of external genital warts, but none of these three treatments were highly successful.