We studied 15 patients with renal cell carcinoma invading adjacent organs (stage T4) between January 1980 and December 1991. Such invasion was four times more frequent in males than in females. The patients were between 41 and 78 years old, with a mean age of 63.9 years. The tumor was on the right side in 4 cases, and on the left side in 11 cases. Six patients (40%) presented with flank pain. The pancreas was the organ involved most frequently. Eleven patients had regional lymph node involvement or distant metastasis. Most patients had an increased erythrocyte sedimentation rate (ESR), elevated alpha-2 globulin levels, and positivity for c-reactive protein (CRP). In 6 patients, nephrectomy was extended to the abdominal or retroperitoneal structures that seemed to be invaded by tumor. Patients with T2 or T3 tumor had a significantly longer overall survival than patients with a T4 tumor. However, there was no significant difference in survival between T2/T3 tumors and T4 tumors in nephrectomized patients. Two patients who survived longer than 3 years showed no abnormalities of ESR, alpha-2 globulin and CRP. They also had no nodal or distant metastases, and had a good initial performance status. These findings suggest that extended local resection can improve the survival and quality of life for selected patients with T4 tumors.