43 diabetic patients on hemodialysis (n = 26) and peritoneal dialysis (n = 17) underwent nutritional assessment by weight, midarm muscle circumference (MAMC), serum albumin, transferrin, prealbumin (PA) and retinol-binding protein (RBP). Serum ferritin was measured as an index of iron stores. The mean age was 48.5 years (range 26–76 years); mean length of diabetes was 22.8 years (range 9–50 years), and mean length of dialysis was 11.6 months (range 1–48 months). At the onset of dialysis 8 subjects (19%) were below 85% ideal weight and the mean serum albumin was 3.2 ± 0.4 g/dl. By the time of nutritional assessment 11 subjects (26%) were below 85% ideal weight, 19 subjects (44%) had a MAMC less than the 5th percentile, the mean serum albumin was 3.6 ± 0.5 g/dl, the mean serum transferrin was 124 ± 36 mg/dl, the mean PA was 330 ± 100 µg/ml and the mean RBP was 142 ± 25 µg/ml. There was a significant increase in serum albumin from 3.2 ± 0.4 to 3.6 ± 0.5 g/dl (p < 0.001) during the time of dialysis. Transferrin was low in 88% of the subjects and was negatively correlated with serum ferritin, but not with change in weight or serum albumin. RBP was elevated and PA was normal or elevated in all subjects regardless of nutritional status. By conventional nutritional assessment there is widespread malnutrition in diabetic patients on dialysis with 26% below 85% ideal weight, 41% with a serum albumin less than 3.5 g/dl and 42% with a MAMC less than the 5th percentile. The usual sensitive indicators of visceral protein status, serum transferrin, PA, and RBP, are not useful in dia