Neuropsychological measures were administered to 18 patients with anorexia nervosa shortly after admission to hospital and again after substantial weight gain. These patients were compared with a group of 18 normal weight controls, also tested on two occasions, who were matched for age, sex, and estimated premorbid IQ. At low weight, impairment was evident on tests of attentional-perceptual-motor functions and on tests of visuospatial construction and problem-solving. Learning was less affected. Refeeding resulted in significant improvements in performance.