As part of the Metropolis project--a large-scale investigation of immigration and integration, including well-being of immigrants in a number of areas of social life--in this paper we investigate the social determinants of health in Canada's immigrant population using Canada's National Population Health Survey (NPHS). Specifically, we examine differences in health status and health care utilization between immigrants and non-immigrants, immigrants of European and non-European origin, and immigrants of < 10 years and > 10 years' residence in Canada. We also examine social determinants of health care utilization and health status in immigrants and non-immigrants, and evaluate the utility of large-scale, national databases for these purposes. Our conceptual approach draws upon a 'population health' perspective, which suggests that the most important antecedents of human health status are not medical care inputs and health behaviours (smoking, diet, exercise, etc.), but rather social and economic characteristics of individuals and populations. We find no obvious, consistent pattern of association between socio-economic characteristics and immigration characteristics on the one hand, and health status on the other, in the NPHS data. This does not mean that socio-economic factors in Canada are not influential in shaping immigrants' health status. In fact, the results of the logistic regression models calculated for immigrants and non-immigrants on four outcome variables in this study suggest that socio-economic factors are more important for immigrants than non-immigrants, although in ways that defy a simple explanation. The complexity of immigrants' experiences, combined with the inherent limitations of cross-sectional survey data are discussed as major limitations to this kind of research.