Objectives: To identify dietary and lifestyle variables that may affect cognitive function in the elderly.Design: Population-based prospective cohort study.Setting: General community residing in Athens and the surrounding Attica region of Greece.Subjects: A total of 732 men and women, 60 years or older, participating in the EPIC–Greece cohort (European Prospective Investigation into Cancer and Nutrition) and residing in the Attica region had sociodemographic, anthropometric, medical, dietary and lifestyle variables ascertained at enrolment (1993–1999). Six to 13 years later, cognitive function was evaluated through the Mini-Mental State Examination (MMSE) score and affective state through the Geriatric Depression Scale (GDS).Results: MMSE score was positively associated with years of formal education, height and physical activity and inversely with age, diabetes mellitus and GDS score (P < 0·05 for all). Among dietary variables, intake of PUFA was inversely associated with cognitive function and this association was largely accounted for by a similar association with seed oils. Adherence to the Mediterranean diet, as well as intake of olive oil, MUFA and SFA exhibited weakly positive but not significant associations.Conclusion: Physical activity and early life factors as reflected in height are significant predictors of cognitive function in the elderly. Seed oil consumption may adversely affect cognition, whereas other nutritional factors do not appear to have a quantitatively large effect.