PURPOSE: This report describes the clinical course of three siblings, all of whom had Evans syndrome in childhood. PATIENTS: The coexistence of autoimmune hemolytic anemia and thrombocytopenia, in the absence of a known underlying cause, led to the diagnosis of Evans syndrome in a 4-month-old girl and subsequently in her two brothers when they were 4 and 13 years old. RESULTS: The 4-month-old girl had a life-threatening relapsing course unresponsive to corticosteroids, intravenous gamma-globulin, thymectomy, and cyclophosphamide. She eventually responded to splenectomy. Her two brothers had milder disease that responded to corticosteroids. Cytogenetic analyses revealed the presence of a familial Y;15 translocation in all three children and their father. CONCLUSION: There are few reported cases of familial Evans syndrome, and they are usually associated with an inherited congenital abnormality. We report the unusual finding of three siblings with the disease and no known congenital abnormality.