Epidemiological Clinicopathological Studies in Europe (EClipSE) is the harmonization of neuropathological and longitudinal clinical data from three population-based prospective longitudinal studies of aging. The EClipSE database (Version 1.0) comprises data from the first 970 people who donated their brain at death and this number will increase. EClipSE enables sociodemographic, health, cognitive, and genetic measures collected during life to be related to neuropathology at death, testing hypotheses which require more power than has been previously possible. EClipSE aims to help throw light on relationships between biological, health and psychological factors underlying ageing and the manifestation of clinical dementia.