In protein-calorie malnourished children, with or without associated vitamin A deficiency, skin content of acid mucopolysaccharides (MPS) and urinary excretion of MPS and amino sugars were studied. MPS content of skin in both malnourished groups was increased 3-6-fold. This increase was essentially in the non-sulphated component. In normal skin, non-sulphate MPS accounted for 68% of the MPS content, whereas in the malnourished group with vitamin A deficiency it constituted 93%. Urinary excretion of MPS (24h) was significantly reduced by 50-70% in malnourished groups. This returned to normal levels in the malnourished/vitamin A deficient group when vitamin A injections were administered. Excretion of amino sugars (24 h) in the malnourished groups was also decreased by 50-70%. In normal children 55% of the total amino sugars was dialysable whereas in the malnourished it was increased to 60%. The excretion of protein-bound and dialysable amino sugars was increased to normal level only in the group given supplements of vitamin A in addition of protein and calories.