The risk of non-ocular cancer has been investigated in 150 surviving Danish patients with retinoblastoma diagnosed in the period 1943-1984. None of the patients had been treated with chemotherapeutic drugs. The overall relative risk of non-ocular cancer was 4.2 (95% confidence limits, 1.1-11.5). In the subgroups of hereditary retinoblastoma, the relative risk was 15.4 (95% confidence limits, 2.6-50.8), and in the subgroups of non-hereditary retinoblastoma the relative risk was 1.7 (95% confidence limits (0.1-8.5). The risk of cancer among 267 parents of retinoblastoma children was not different from that of the general population.