The food intake and the nutritional status of 100 chronic renal failure patients on maintenance hemodialysis in 10 facilities in the city of São Paulo were studied. The average food intake obtained through 3 days of dietary diaries showed a caloric intake of 26.6 +/- 10kcal/kg/day (mean +/- SD), 24% below the minimum daily caloric intake recommendation and a protein intake of 1.03 +/- 1.4g/kg/day which averaged the minimum recommended for chronic renal patients on hemodialysis. The average intakes of calcium (418.6 +/- 294.9mg), phosphate (813.5 +/- 335.2mg) and iron (10.5 +/- 4.9mg) were also low. Mean serum albumin was 3.9 +/- 0.7g/dl and only 3.1% of the patients had albumin levels below 3.0g/dl. There was no difference between the real and ideal body weight. On the other hand 69% of women and 25% of men had the triceps skin fold (TSF) in the 5th percentile while 24% of women and 79% of men exhibited values of the muscle arm circumference (MAC) in the same percentile. Moreover there were inverse and significant correlations between the time on dialysis and TSF for women (r = -0.19) and the time on dialysis and MAC for men (r = -0.16). This study shows that our patients on hemodialysis have a poor food intake, with marked reduction of fat and muscle stores. The undernourished state observed tended to be more pronounced with the duration of the dialysis treatment and could influence negatively on the morbidity and mortality of these patients.