From 1968 to 1983, in the Department of Urology and in the Institute of Radiotherapy of the University of Brescia, the role of postoperative radiotherapy (PORT) in 95 patients with renal adenocarcinoma (T2-3 N0 M0) was investigated. From 1968 to 1978, 46 patients underwent radical nephrectomy and PORT; from 1978 to 1983, 49 patients were submitted to radical nephrectomy with regional lymphadenectomy (CH). Overall survival (PCS) at 5 years is 63% (PORT) vs 57% (CH) (p greater than 0.05). The probability of survival is better for left-sided neoplasms than for right-sided ones. In the CH group, the 5-year PCS is 40% vs 70%, respectively, for right vs left neoplasms (p less than 0.05); in the PORT group, PCS is 59% (right) vs 70% (left). For right-sided cancers, 5-year PCS is higher for PORT (59%) than for CH (40%) patients (p less than 0.05). In the PORT group acute bowel toxicity was 24% (grade 2, WHO). In 2 patients only (4.3%) PORT was stopped because of toxicity. PORT sequelae were investigated in: spinal cord, contralateral kidney, liver and bowel. Bowel sequelae (grade 2, Dische) were observed in 3 patients only (6.5%). In the T2-3 N0 M0 classes, radical nephrectomy with PORT may give the same results as aggressive surgery, with a low biological cost. Prognostic data might mean a different and more favorable loco-regional evolution for left-sided renal cancers.