In The Netherlands, as in many other industrialized countries, recent mortality developments have been characterized by rapid declines for a number of important causes of death. The results of an analysis of regional variation in mortality decline within The Netherlands are reported, covering the period 1969-1984. The causes of death included in this analysis are Perinatal mortality, Cerebrovascular disease, a more global 'Amenable' selection (formed by aggregating a number of causes of death considered to be amenable to medical intervention), Cancer of the stomach, Ischaemic heart disease and Traffic accidents. For Perinatal mortality, Cerebrovascular disease, the 'Amenable' selection, and Ischaemic heart disease, as well as for Total mortality, declines have not been geographically homogeneous. Perinatal mortality had a tendency to decline faster in regions where starting levels were higher, suggesting a certain convergence. For Cerebrovascular disease and the 'Amenable' selection, but especially for Ischaemic heart disease, the reverse was true. A simple correlation analysis shows that for Perinatal mortality, as well as for the 'Amenable' selection, mortality declined faster in less urbanized, more peripherally located, lower income areas. There is no association with the presence of a university hospital. This pattern suggests that faster mortality decline for these conditions is due to factors other than faster diffusion of new medical technologies. For Ischaemic heart disease, mortality declined faster in more urbanized, more centrally located, higher income areas. Although this pattern is what one would expect as a result of regional differences in the diffusion of new medical technologies, it may also be due to differences in the diffusion of new lifestyles.(ABSTRACT TRUNCATED AT 250 WORDS)