The anatomical and physiological changes of aging make elderly people a vulnerable group to malnutrition and specific deficiencies of nutrients such as vitamin B12 and folate. This study was aimed to establish relationships among serum vitamin B12, folate, homocysteine concentrations and dietary intake and adequacy. Fifty five male and female elderly (60 and more years), free-living, were assessed. Measurements were: serum vitamin B12 and folate by radioimmunoanalysis (RIA), homocysteine by polarized fluorescence immunoassay, nutrient intake by three 24 hours recalls and food frequency questionnaire. Nutritional status was determined by Body Mass Index (BMI). Serum vitamin B12 and folate were at normal range (423,3+/-227,6 pmol/l and 6,4 +/- 4,5 mg/ml), but 17,5% of elderly had B12 deficiency and 12% had folate deficiency. Serum homocysteine was higher than reference values (15,8+/-4,4 mmol/l), but 47,5% showed concentrations above 15 mmol/L, male population showed higher mean value (p: 0,01). Nutrient intake was inadequate by deficiency. BMI indicated 11,8% of undernutrition, 29,4% of overweight and 20,6% of obesity A negative and inverse correlation between homocysteine and serum folate was found. Results suggest a biochemical deficiency of B12 and folate that is expressed as elevated homocysteine levels. These finding represent a high cardiovascular risk factor for this elderly group.