Twenty women with cervical and vaginal human papillomavirus-associated lesions were treated with CO2 laser ablation followed by eight weekly applications of 5-fluorouracil. Viral subtyping in a majority of patients and histology were obtained before and after treatment. After treatment 88% (15 of 17) had normal vaginal biopsies, and 59% (10 of 17) had normal cervical biopsies. There were no treatment failures with subtype 6/11 infection of the cervix or vagina. All the failures were with viral subtypes 16/18 and 31/35/51. The protocol was effective in treating patients with cervical and vaginal human papillomavirus-associated lesions.