[영문]This paper proposes an empirical implementation of the concept of inequality of opportunity in health and applies this to data from the UK National Child Development Study. Drawing on the distinction between circumstanceand effortvariables in John Roemers work on equality of opportunity, circumstancesare proxied by parental socioeconomic status and childhood health; effortis proxied by healthrelated lifestyles and educational attainment. Stochastic dominance tests are used to detect inequality of opportunity in the conditional distributions of selfassessed health in adulthood. Two alternative approaches are used to measure inequality of opportunity. Econometric models are estimated to illuminate and quantify the triangular relationship between circumstances, effort and health. The results indicate the existence of a considerable and persistent inequality of opportunity in health. Circumstances affect health in adulthood both directly and through effort factors such as educational attainment. This indicates that, while the influence of some unjust circumstances can only be tackled during childhood, the implementation of complementary educational policies may be of paramount importance