Infant mortality in Third World countries is still a major health problem; overall, there has been progress over the past three decade, but it is unevenly distributed. Some Third World countries have achieved significant declines in infant mortality, while others have not. The expectation – rising from the historical experience of industrialized countries – that infant mortality will decline concurrently with the process of economic development has not, in general, been borne out. This paper applies a “political economy of health” perspective to infant mortality and seeks to account for discrepancies between economic progress and progress against infant mortality. It traces out a four-fold comparison – between countries with high/low economic development and countries with high/low infant mortality – for testing hypotheses in the political economy of health.