Background: This paper explores newly available data for 22 countries with reliably recorded mortality data. The past century saw dramatic falls in mortality for both males and females in the most affluent countries of the world. However, these falls are not consistent for both men and women and the inequalities in the male:female mortality ratios are not well understood. Design: By aggregating mortality at each year of life for the 22 countries for those years for which reliable data were recorded (during the period 1850–1999), distinct patterns emerge. Results: In the richer countries of the world, the male:female mortality ratio has been widening for all years of age, particularly for those born from 1942 onwards. Specific cohort effects are clearly identifiable. Conclusion: Analysis of the emergent trends suggests that economic activity, status and position possibly provide a better overall explanatory model than a purely biomedical approach.