Study objective: To study the association between cognitive impairment and early death in elderly patients living in the community. Design: Case-control study of 410 patients assessed by the mental status questionnaire and followed up after three years. Setting: A general practice in Inverurie, Aberdeenshire, with 14000 patients. Patients: 205 Patients aged ≥65 with cognitive impairment according to the mental status questionnaire (score ≤8) and 205 patients scoring >8 on the questionnaire matched for age and sex. Main outcome measure: Death. Results: The relative risk of death in the cognitively impaired patients overall ws 3.5. Those patients who scored ≤7 on the mental status questionnaire were five times more likely to die than their controls. There was no difference in risk of death between those with severe or moderate cognitive impairment. Conclusions: Cognitive impairment is associated with early death.