The etiology of Kienbock's disease, avascular necrosis of the carpal lunate, is unknown. Causal factors are implied by their prevalence in the literature. The role of heredity in Kienbock's disease has not been addressed. This report documents the familial occurrence of Kienbock's disease in a mother and daughter and raises the possibility of a genetic contribution. Kienbock's disease is the eponym designating avascular necrosis of the carpal lunate 2,4.