Our aim was to evaluate remission and relapse rates and the number of laser sessions necessary for treatment. Among the relapses observed, we sought to differentiate between the persistence and recurrence of an HPV-induced lesion. This retrospective study was performed in patients, immunocompetent or not, treated with CO2 laser for condylomatous or neoplastic anogenital lesions by the same operator over a period of 12 months. 106 treated patients were followed for 6 months. Three groups of patients were analysed: HIV(+) patients, patients with therapeutic immunosuppression (ImST) and immunocompetent patients (ImC). Twenty-seven (25.5%) patients presented with high-grade intraepithelial neoplasms (IEN III). IEN III lesions were more common in the HIV(+) group than in immunocompetent patients (47.4% versus 20.2%, p = 0.015). The development of HPV-induced lesions at several sites on the body was also more common in HIV(+) patients. Post-laser controls at one month demonstrated a clinical absence of HPV-induced lesions in 81.2% of cases, recurrence in 12.6% of cases and persistence in 6.6% of cases. Remission rates at one month did not differ significantly between the three groups. 93% of patients in remission at one month were still in remission at three months. IEN III neoplasms in remission at one month remained so at six months. ImC and ImST patients presented more frequently with recurrence than persistence, when compared with HIV(+) patients. At six months, 83% of patients were in remission after 1.4 laser treatments. The excision of HPV-induced anogenital lesions using CO2 laser remains an efficient treatment, even if it needs to be repeated if lesions recur or persist. CO2 laser treatment under colposcopic guidance can achieve remission in both immunocompromised and non-compromised patients with longstanding lesions.