Over forty studies published between 1970 and 1995 are reviewed to identify the extent and nature of risks to siblings of chronically ill children, and the factors that may increase or lower the risks. A considerable amount of research is available in this area within the Untied States, but is relatively understudied elsewhere. About 60% of the studies reported an increase in sibling risk, while 30% reported no risk; and 10% had positive and negative outcomes. Interventions need to focus on the entire family system.