The kinetic changes responsible for decreased plasma albumin and the relation between plasma albumin and the edema of protein-energy malnutrition (PEM) were investigated by measuring the plasma concentration, fractional (FSR) and intravascular absolute (ASR) synthesis rates of albumin in seven edematous and seven nonedematous children with PEM by using constant intragastric infusions of [2H3]leucine. Studies were done 2 d postadmission (study 1), 8 d postadmission (study 2), and at recovery (study 3). In study 1 there were no significant differences in plasma albumin concentrations in nonedematous and edematous children. In both groups, albumin concentrations but not FSRs were lower in studies 1 and 2 than in study 3. The ASR was lower only in edematous patients. These results suggest that repletion of the albumin pool of children with PEM is not mediated by changes in the FSR, and the edema of malnutrition is not solely due to hypoalbuminemia.