The finding that mortality differences between occupational classes in England and Wales have widened during the postwar period raises the question whether a similar development has occurred in other industrialised countries. In this paper, a comparison is made with results from a geographical study on the Netherlands. This study compares four periods between 1950 and 1984 by means of a standard regional division, a single socio-economic index, uniform cause-of-death groups and a standard regression procedure. During the postwar period, the relationship between socio-economic level and all-cause mortality has become (more) negative. This development can to a large extent be attributed to 'negative' trends for lung cancer, diabetes mellitus, ischaemic heart disease, cerebrovascular disease and traffic accidents. High-level regions have fared better partly because favourable changes in national mortality trends seem to have begun first in these regions. The findings from this regional study agree to a large extent with evidence from Dutch studies at the individual level. It is concluded that socio-economic mortality differences in England and Wales and the Netherlands have probably developed similarly in various respects.