It has been reported that essential fatty acid levels may be low and that there may be reduced levels of delta-6-desaturase metabolites of linoleic acid in patients with atopic eczema. Good therapeutic results have been reported on the use of evening primrose oil (Efamol) in adults but not in children. Efamol contains gamma-linolenic acid, the delta-6-desaturase metabolite of linoleic acid. The authors have studied 24 children with atopic eczema: 12 of them were treated with a higher dose of evening primrose oil than in previous studies and 12 with placebo olive oil. The clinical status and plasma, neutrophil and lymphocyte fatty acid composition in these children have been evaluated. After 4 weeks the eczema of essential fatty acid-treated children significantly improved in comparison with that of placebo-treated children (p less than 0.01). There were significant changes in plasma fatty acid composition between the basal values and the end of active treatment, and between the placebo and actively treated children. Neutrophil and lymphocyte fatty acid composition did not seem to be related to disease activity.