This article reviews the benefits of BCG maintenance therapy in ment patients with superficial bladder tumours. The rare published studies conclude on contradictory results. These differences can probably be explained by the variability of the protocols used, the small number of patients included, and the heterogeneity of the series (presenting tumours of different stages and grades). In the largest series, that reported by the Southwest Oncology Group SWOG), maintenance therapy significantly reduced the risk of tumour recurrence and progression in carcinomas in situ and recurrent Ta or T1 tumours. The treatment recommended by the SWOG consists of a weekly instillation for 3 weeks 3, 6, 12, 18, 24, 30 and 36 months after induction therapy.