The authors established a protocol for the use of 5-fluorouracil (5FU) adjuvant in lasertherapy for clinical and subclinical HPV infection in immunosuppressed patients, persistent lesions and as reinforcement treatment in cases of poor progress. Sixty-four patients were evaluated, of whom 26 were immunosuppressed, 34 presented persistent lesions and four received intravaginal reinforcement treatment with 2.5 g 5% 5FU every two weeks, or biweekly vulvar reinforcement after lasertherapy. On average, five 5FU courses were used, but in the immunossuppressed patients its use was maintained indefinitely. The rate of complete response was 66%, but the immunossuppressed patients showed less response (46.2%) when compared with the persistent lesion/reinforcement treatment group (78.9%). The responses were positive in the two groups when compared to that with no response. We deem the use of low-dose 5FU an excellent alternative in cases of difficult HPV progress, presenting a low cost and minimal side-effects.