The relation between social, economic, and family life event measures and rates of hospital admission during the period from birth to 5 years was studied in a birth cohort of New Zealand children. Both family social background and family life events made a significant contribution to the variability in the risk of hospital admission. However, economic factors made no significant contribution to rates of admission when the correlated effects of family social background and life events were taken into account. In addition, the effects of family life events on risks of admission appeared to be far more marked than the effects of family social background. Possible explanations of the consistent association between life events and rates of morbidity during early childhood are discussed.