Erythrocyte fatty acids and plasma vitamin E concentrations were determined in 47 grade 2 and 21 grade 3 malnourished Pakistani children (ages 4-56 months). Data were compared with those of 26 age- and sex-matched apparently healthy controls. Evaluation with three statistical approaches revealed that both grade 2 and grade 3 malnourished children had decreased erythrocyte omega6 fatty acids and to a lesser extent decreased omega3 fatty acids. These decreases were compensated for by increased omega9 fatty acids. The patients tended to have lower plasma vitamin E concentrations. We conclude that malnourished Pakistani children have low essential fatty acid status, notably those of the omega6 series. The combination of low erythrocyte 22:6omega3 and a low 22:5omega6/22:4omega6 ratio in grade 2 patients suggests low delta4-desaturation activity, which may be due to impaired peroxisomal beta-oxidation.