In order to expand our knowledge of how health inequalities are generated, a broader range of possible mechanisms has to be studied. Two mechanisms of potential importance here are childhood conditions and sense of coherence. Drawing on theoretical arguments and empirical findings in these two research fields, a conceptual model of the relationships between childhood conditions, sense of coherence, adult social class and adult health is presented. On the basis of this model, this paper sets out to analyse (1) the degree to which a low sense of coherence is based in childhood experiences, (2) the degree to which the impact of childhood conditions on adult health is mediated through sense of coherence, and (3) the importance of sense of coherence for class differences in ill health. The analyses are carried out on both cross-sectional data (n = 4390) and panel data (n = 3773) from the Swedish Level of Living Surveys in 1981 and 1991. The analyses indicate that childhood family size and the experience of a broken home are unrelated to sense of coherence later in life, while economic hardship has a small and indirect effect, mediated via class position in adulthood. Only dissension in the childhood family was found to have a direct, although fairly modest, effect on sense of coherence. Furthermore, it is demonstrated that sense of coherence does not mediate the effect of childhood factors on adult health. Rather, childhood conditions and adult sense of coherence appear to be complementary and additive risk factors for illness in adulthood. The results presented here also suggest that sense of coherence may be a factor involved in the shaping of class inequalities in health.