Of the 44 patients seen during the period January 1 9 7 4 t o March 1 9 7 9 with category T 3 or T 4 bladder cancer, 3 3 were treated by partial or total cystectomy followed by adjuvant chemotherapy with high dose methotrexate and folinic acid rescue (HDMTX-CF), with a survival rate a t 2 years of 9 0 % . Two patients were given palliative treatment with HDMTX-CF alone; one of them is alive and disease-free after 39 months.A study of recent publications on the treatment of infiltrating tumours of the bladder shows that this disease is too frequently treated as a local condition with local treatment, i.e. surgery or radiotherapy or a combination of both. In fact, patients suffering from infiltrating bladder cancer should be considered as having a systemic disease, or at least a disease that has the potential for systemic involvement. It follows that if the therapeutic objective is cure, therapy should contain a systemic element.This hypothesis assumes clinical importance when the results of local treatment alone of infiltrating bladder cancer are considered. In a review of the English language medical literature, Jewett (1970) showed that the results of total cystectomy alone were poor, the 5-year survival rate for patients with category T3 and T4 lesions being 9 and 3% respectively. The 5-year survival rate following radiotherapy as primary treatment was little better, being 19 and 1% for patients with T3 and T4 tumours respectively (Kuohara et al., 1965;Cuccia, 1969). Other reports by Morrison and Deeley (1963, Prout et al. (1970), Van der Werf Messing ( 1 9 7 9 , Miller (1 977), and Ellingwood et al. (1 979), using surgery combined with radiotherapy, have shown improved results but there is clearly considerable scope for improvement and a satisfactory approach to the treatment of infiltrating bladder tumours has yet to be found. In this study which concerns patients with category T3 and T4 lesions we have used adjuvant chemotherapy with high