With the increasing awareness of incipient and subclinical malnutrition in children several nutritional indices have been suggested for the early recognition of protein-energy malnutrition (PEM). We evaluated plasma albumin, transferrin, and fibronectin levels in 15 children with PEM and compared them with those of 10 well-nourished children. The results demonstrated that plasma albumin is a poor indicator of mild to moderate PEM. On the other hand, plasma transferrin and fibronectin are sensitive indicators of PEM as they were significantly decreased in our mild to moderately malnourished children whereas albumin was unchanged. Furthermore, malnourished children showed iron deficiency anaemia, which may interfere with the results of plasma transferrin determinations. Fibronectin is believed to have a functional role in coagulation, host immune defence, and wound healing. We suggest that the assay of fibronectin may provide a biochemical functional index of mild to moderate nutritional deficiency before overall depletion has occurred.