Adult survivors of childhood cancer are known to be at increased risk of subsequent malignancy, but only limited data exist describing the incidence and risk factors for secondary renal carcinoma. Among 14 358 5-year survivors diagnosed between 1970 and 1986, we estimated standardized incidence ratios (SIRs) for subsequent renal carcinoma and identified associations with primary cancer therapy using Poisson regression. Twenty-six survivors were diagnosed with renal carcinoma (median = 22.6 years from diagnosis; range = 6.3-35.7 years), reflecting a statistically significant excess (SIR = 8.0, 95% confidence interval [CI] = 5.2 to 11.7) compared with the general population. Highest risk was observed among neuroblastoma survivors (SIR = 85.8, 95% CI = 38.4 to 175.2) and, in multivariable analyses, with renal-directed radiotherapy of 5 Gy or greater (relative risk [RR] = 3.8, 95% CI = 1.6 to 9.3) and platinum-based chemotherapy (RR = 3.5, 95% CI = 1.0 to 11.2). To our knowledge, this is the first report of an association between cisplatin and subsequent renal carcinoma among survivors of childhood cancer.