One of the most established dimensions of inequality in mortality is regional variation. However, studies that investigate regional mortality patterns across national borders are extremely rare. We respond to this gap in the literature by carrying out a comparative study in Finland and Sweden. A comparison of these two countries is of particular interest for several reasons. First, they are neighbors, with a shared history, and similar political and environmental conditions. Second, they have very different national mortality trajectories. Here we investigate the regional differences in gender-specific mortality in both countries and how they have changed over time. We explore these differences using individual-level register data from both countries applying a variety of mortality measures, including life span variation. First results suggest pronounced north-south mortality differences in both countries, larger differences between male and female life expectancy in Finland, and specific patterns for the Swedish-speaking minority regions in Finland.