INTRODUCTION Numerous trials using interferon in the treatment of HPV infections have been reported. IFN-β has antiviral, antiproliferative and immunopotentiating activities. The aim of this randomized open study was to evaluate the effectiveness of intramuscular IFN-β in reducing relapses versus both electrocautery and combined treatment, i.e. IFN-β plus electrocautery, in a group of male patients affected by genital warts.PATIENTS AND METHODS A total of 84 male patients (mean age 32 years) with recent genital warts were randomly enrolled into three groups: 33 patients were treated with electrocautery; 25 patients received only intramuscular IFN-β (3 000 000 IU daily for 10 days); 26 patients were treated with both electrocautery and intramuscular IFN-β (3 000 000 IU daily for 10 days). The patients were checked monthly. Residual disease was treated with electrocautery until complete clearance.RESULTS After 1 month 42% of the patients treated with electrocautery, 29% of those treated with IFN-β and 39% of those treated with combined therapy had been cured. Residual disease rates gradually decreased in all groups during the follow-up, but more quickly in the patients who had received IFN-β therapy. No side-effects after IFN-β treatment were observed.CONCLUSION IFN-β monotherapy is not the first choice treatment for genital warts, though it may be useful in patients with relapsing condylomata acuminata resistant to other therapy.