When effective treatments against neurodegenerative diseases become a reality, it will be important to know the age these pathologies begin to develop. We investigated alpha‐synuclein pathology in brain tissue of the Tampere Sudden Death Study—unselected forensic autopsies on individuals living outside hospital institutions in Finland. Of 562 (16–95 years) participants, 42 were positive for Lewy‐related pathology (LRP). The youngest LRP case was aged 54 years, and the frequency of LRP in individuals aged ≥50 years was 9%. This forensic autopsy study indicates LRP starts already in middle age and is more common than expected in the ≥50 years‐of‐age non‐hospitalized population. ANN NEUROL 2024;95:843–848