The Authors present the preliminary results of a feasibility study on the use of adjuvant radiotherapy (6 Gy single fraction, postoperatively, "flash") as a new treatment modality for superficial bladder cancer (Ta-T1, N0, M0, previously relapsed or not, G I-III). The rationale for this study derives mainly from the favourable results obtained with external beam radiotherapy, when applied before interstitial radiotherapy as a method to avoid scar relapses. Data regarding 55 cases treated with the "flash" are compared retrospectively with those regarding more than 100 cases treated with different types of "conventional" adjuvant therapy at the INRCA Center of Urology, during the last 3-4 years. The Authors stress the need for a prospective, randomized study of selected cases, to clarify if an adjuvant therapeutic modality is superior to the others. The radiotherapeutic option ("flash"), however, clearly produces less iatrogenic damage than the others, and is simpler and cheaper.