A total of 146 patients with invasive or locally advanced carcinoma of the bladder (T2-T4) underwent radiation treatment. A significantly higher complete response rate was observed with doses equal to or above 55 Gy and with doses corresponding to cumulative radiation effect (CRE) values of 1700 radiation effect units (reu) or more. In multivariate analysis, decreasing time from the first diagnosis of bladder carcinoma to radiation treatment and 1 or more transurethral resections was associated with a significant increase in survival; increases in T category and sedimentation rate were negative prognostic factors. Although both radiation dose and CRE levels had a significant effect on survival in univariate analysis, an increase in CRE levels alone was associated with a significant increase in survival in multivariate analysis. However, the most important predictor of survival was whether the patient showed a complete local response or not. This study emphasises the importance of treating patients with an adequate radiation dose over a short period of time in order to achieve the maximum radiobiological effect and thereby increase the possibility of cure.