We have studied protein metabolism and nutritional status in a group of patients in regular dialysis treatment. In forty-five patients (mean age 58 +/- 11 yr), undergoing maintenance hemodialysis we have measured protein (DPI) ad caloric (CI) intake by a three-day dietary recall. Protein catabolic rate (PCR) using the urea kinetic model (Gotch' variable volume), anthopometric parameters such as weight, height, midarm circumference, skinfold thickness, midarm muscle circumference (AMC), midarm muscle area (AMA), total muscle mass (TMM) and the percentage of body fat were measured as well. PCR was weakly correlated with DPI. TMM showed a direct relationship with DPI and correlated inversely with UNA/NI (Urea Nitrogen Appearance/Nitrogen Intake). 18% of patients were underweight; 17% showed a decrease of AMA. TMM was inversely correlated with total hospitalization days. There were no significant variations of the examined parameters in a year later evaluation. In our experience TMM is the parameter which better correlates with clinical findings.