The nutritional status of 145 black preschool children aged 3-5 years living in Letaba near Tzaneen was evaluated biochemically; 20.7% weighed less than 80% of the 50th percentile. Mean levels of red cell thiamine, serum protein and albumin, 25-hydroxyvitamin D, alkaline phosphatase, calcium and phosphorus were similar in underweight children and children not classified as underweight. The precise bearing of slower growth and associated biochemical parameters on present and future health needs elucidation.