The purpose of the study was to examine the association of plasma lipid concentrations with changes in cognitive function and depressive states in elderly Greek individuals. The study population consisted of 3 groups: A) 37 subjects with dementia, B) 33 subjects with depression, and C) 33 controls. All individuals were screened with the Mini-Mental State Examination (MMSE), the Geriatric Depression Scale (GDS), and an evaluation of their psychiatric state. Lipid profile was assessed in all subjects, and the results were statistically evaluated at P < .05 level of significance. Groups A and B had significantly lower levels of total plasma cholesterol and HDL cholesterol than group C (P < .01). Triglyceride levels did not differ significantly between groups A and C, although they were significantly higher in group B. The results of this study suggest that an association does exist between the plasma concentration of cholesterol and HDL-C and depression and/or cognitive impairment. Further studies are required to explore the significance of these observations and establish if lipid levels could serve as markers for diagnostic and therapeutic purposes.