Four-hundred consecutive referrals with viral warts of the hands and/or feet were investigated to determine the cure rate from a combination of cryotherapy, keratolytic wart paint and paring. For treatment failures after 3 months, the value of continuing cryotherapy and of additional treatment with the immunomodulator inosine pranobex were assessed. Subjects were treated for 3 months with wart paint and cryotherapy and were randomized to receive, or not, paring in addition. Those who did not respond by 3 months were randomized to receive, or not, 3 months further cryotherapy, and to receive inosine pranobex 60 mg/kg/day for 1 week each month, or matching placebo. Fifty-two per cent of subjects were cured by 3 months. The chance of cure was inversely related both to the length of history and to the diameter of the largest wart. Paring improved the cure rate for plantar warts but not for hand warts. During the second 3 months the cure rate fell to 41%. Neither cryotherapy nor inosine pranobex significantly improved this response.