Background Studies of period changes in educational inequalities in mortality have shown important changes over time. It is unknown whether a birth cohort perspective paints the same picture. We compared changes in inequalities in mortality between a period and cohort perspective and explored mortality trends among low-educated and high-educated birth cohorts.

Data and methods In 14 European countries, we collected and harmonised all-cause and cause-specific mortality data by education for adults aged 30–79 years in the period 1971–2015. Data reordered by birth cohort cover persons born between 1902 and 1976. Using direct standardisation, we calculated comparative mortality figures and resulting absolute and relative inequalities in mortality between low educated and high educated by birth cohort, sex and period.

Results Using a period perspective, absolute educational inequalities in mortality were generally stable or declining, and relative inequalities were mostly increasing. Using a cohort perspective, both absolute and relative inequalities increased in recent birth cohorts in several countries, especially among women. Mortality generally decreased across successive birth cohorts among the high educated, driven by mortality decreases from all causes, with the strongest reductions for cardiovascular disease mortality. Among the low educated, mortality stabilised or increased in cohorts born since the 1930s in particular for mortality from cardiovascular diseases, lung cancer, chronic obstructive pulmonary disease and alcohol-related causes.

Conclusions Trends in mortality inequalities by birth cohort are less favourable than by calendar period. In many European countries, trends among more recently born generations are worrying. If current trends among younger birth cohorts persist, educational inequalities in mortality may further widen.