Survivors of retinoblastoma (Rb) are at high risk of dying from second malignant tumour. The occurrence of second malignant neoplasm (SMN) and related mortality in a cohort of 1111 cases from the Italian Retinoblastoma Registry was analysed, considering the possible role of both genetic and iatrogenic causes. Rb patients had a greater than 10-fold excess in overall mortality compared with the general population (standardized mortality ratio (SMR) 10.73, 95% CI 9.00-12.80). Their excess risk attributable to cancers other than Rb was 14.93 95% CI 10.38-21.49). Survivors of hereditary Rb had an SMR for all causes of 16.25 (95% CI 13.20-20.00), whereas their SMR for all cancers was 25.72 (95% CI 17.38-38.07). Survivors of unilateral sporadic Rb had an SMR of 4.12 from all cancers (95% CI 1.55-10.98) and a much higher excess for overall mortality (SMR 13.34, 95% CI 10.74-16.56). As expected, survivors of hereditary Rb had higher mortality from cancers of the bone (SMR 391.90, 95% CI 203.90-753.20) and soft tissue (SMR 453.00, 95% CI 203.50-1008.40), small intestine (SMR 1375.50, 95% CI 344.00-5499.70), nasal cavity (SMR 13.71, 95% CI 1.93-97.35) and cancers of the brain and central nervous system (SMR 41.14, 95% CI 13.2-127.55).