Data from four pediatric hospitals concerning 20 children treated for renal cell carcinoma (RCC) from 1964-1978 were reviewed. Median age of the patients (pts) was 11.8 years (range, 14 months-19 years). Twelve were male and eight female; 17 were white and three black. Most patients presented with pain and hematuria with or without a palpable mass. An intrarenal tumor was detected at IV urography (17 pts), arteriography (2 pts), or at surgery (1 pt). Treatment consisted of nephrectomy in 15 pts, renal biopsy (4 pts), or no surgery (1 pt), followed by chemotherapy (5 pts), radiation therapy (1 pt), or both (7 pts). Ten pts died of distant metastases at a median of one year (range, 0.2 to two years) after diagnosis. The other 10 pts (50%) survive free of relapse at a median of 4 years (range, two to ten years) from diagnosis. Proportions surviving free of recurrent disease two or more years by National Wilms' Tumor Study (NWTS) Group were 5/5 in Group I, 3/7 in Group II, 1/3 in Group III, and 1/5 in Group IV; by age at diagnosis, 6/6 in those under 11 years old and 4/14 in those 11 or older; and by type of surgery, 10/15 who had nephrectomy and 0/5 with limited or no surgery. The data indicate that radiation and chemotherapy had only minor if any influences on relapse-free survival. We conclude that (1) RCC in children is similar to its counterpart in adults; (2) RCC has a worse prognosis than Wilms' tumor except for the earliest stage; (3) nephrectomy alone is adequate treatment for Group I RCC, and (4) young age (less than 11 years old) may be prognostically favorable.