This study examines the long-term association between income and life expectancy in Sweden between 1960 and 2021. The study is based on register data that include all Swedish permanent residents aged 40 y and older. The results show that the gap in life expectancy between the top and bottom income percentiles widened substantially: For men, it increased from 3.5 y in the 1960s to 10.9 y by the 2010s, and for women, from 3.8 y in the 1970s to 8.6 y by the 2010s. Despite a reduction in income inequality and an expansion of social spending from the 1960s to the 1990s, health inequality continuously increased over the period under study. The changes of the relation between real income and life expectancy, the so-called Preston curve, reveal a much faster improvement in life expectancy in the upper half of the income distribution than suggested by the cross-sectional relation between income and life expectancy. Analysis of causes of death identified circulatory diseases as the main contributor to improved longevity, while cancer contributed more to the increased gap in life expectancy for women and equally for men. Finally, analysis of the change in the income gradient in avoidable causes of death showed the strongest contribution of preventable causes, both for men and women.