We aimed to assess the effectiveness of an educational leaflet to modify sexual risk behaviour in women with external genital warts. Women with genital warts who attended in daily gynecological practice participated in a 12-month prospective randomised observational study. Randomisation was carried out by centres. At the initial visit, patients underwent complete gynecological examination, including an acetic acid test. Those assigned to the intervention group received an educational leaflet to improve patient's knowledge about warts (counselled group). Only patients with complete clearance after 6 months of initial therapy continued the study. The counselled group included 114 women and the non-counselled group 97. A significant increase in the use of condoms at visit 3 as compared with baseline (83.2% vs 66.1%, P < 0.05) was observed in the counselled group. The mean number of sexual partners was also significantly lower in the counselled group at each follow-up visit. Recurrences were documented in 9 of the 145 patients who completed the study (recurrence rate 6.2%). Recurrences occurred in 7 patients in the counselled group and in 2 in the non-counselled group (8.6% vs 3.1%, P = 0.299), and in all cases occurred at 9 months after initiation of treatment. In conclusion, the educational leaflet, which is simple and easy to implement in routine daily practice, proved to be effective in modifying sexual risk behaviour in women with external genital warts. This educational strategy did not seem to affect recurrence if an acetic acid test is routinely performed during the initial work-up studies.