Forty children with atopic eczema requiring topical steroids entered a double-blind group comparative study over 12 weeks and were randomized to either 4% sodium cromoglycate (SCG) in an oil-in-water cream or matching placebo cream. The eczema was evaluated on area charts for 20 parts of the body at five clinic visits. In addition, the families kept diaries on symptoms and treatment. After 3 weeks there were small but statistically significant decreases in severity scores recorded at the clinical visits in the SCG group compared with small increases in the placebo group. However, there were no statistically significant differences in the diary card data during the first 3 weeks of treatment or in any other period, nor were significant differences found in any efficacy data collected during the other 9 weeks of the trial. There were no marked differences in treatment opinions, unusual symptoms, skin infections, use of topical steroids or drugs, or acceptability data between the groups. Staphylococcus aureus was found once or twice in cultures from eczema lesions in 31 of 40 children with no marked group difference. The trial showed that there is great need for improved information, family support and topical as well as general treatment in childhood atopic eczema, but topical SCG did not relieve the patients' eczema.