The treatment and relapse rate of genital warts are significant problems. The aim of this observational study was to assess the efficacy of holmium laser treatment of genital warts. A total of 1500 outpatients with genital human papillomavirus-induced lesions presenting from August 2002 to June 2005 were treated with holmium laser. The effects and side-effects of treatment were observed and analysed. Of this large cohort, lesions were excised at the first visit in 1488 cases. Twelve cases were treated a second or third time in the event that the lesions were too large to be removed at the first visit. The incidence of side-effects and complications after treatment with holmium laser was found to be low. Almost all warts can be excised at first treatment by holmium laser therapy with little bleeding during the treatment.