We treated 414 new patients with stage pTa, grades 1 and 2 bladder tumors by transurethral resection between 1970 and 1982. All of the patients with grade 3 or previous upper tract tumors, or who had been treated at some stage with intravesical chemotherapy were excluded. Followup for 5 or more years was available in 188 of the patients. There was a low increase in T stage (6 per cent). Of the patients followed for 5 or more years 46 per cent remained free of tumor. Only 16 per cent of the patients had multiple tumors at presentation and 20 per cent had tumors of 10 gm. or more. These factors were associated with a worse prognosis. Patients free of tumor at 3 months had an 80 per cent chance of having no further recurrences and this rate remained the same up to 2 years from the start of the disease. Patients with a recurrence at 3 months were much less likely to remain free of tumor, and had a higher chance of recurrence at every future visit.