Thirty-seven patients with previously untreated perianal condylomata acuminata were randomly treated by application of 25 per cent podophyllin or scissor excision. The result of treatment was assessed by an independent observer. At 6 weeks, scissor excision completely cleared the warts from 16 of 18 patients (89 per cent) compared with 15 of 19 patients (79 per cent) treated with podophyllin. Following complete clearance by surgery, two patients had recurrent warts at 18 weeks and a further single patient at 42 weeks, giving a cumulative recurrence rate of 19 per cent. In contrast, five of 15 patients whose warts were cleared by podophyllin had recurrent warts at 18 weeks and a further four at 42 weeks representing a cumulative recurrence rate of 60 per cent (X2 = 3.95, d.f. = 1, P = 0.05). At 42 weeks six patients (32 per cent) were free of disease in the podophyllin group compared with 13 (72 per cent) in the scissor excision group (X2 = 4.6, d.f. = 1, P = 0.03). Scissor excision is therefore preferable to podophyllin application in the treatment of perianal condylomata acuminata.