A randomized, double-blind, left-right study to compare the therapeutic efficacy and the cosmetic acceptability of the new hydrocortisone 17-butyrate (Locoid) 0.1% fatty cream application form with desonide (Apolar) 0.1% ointment was performed in thirty patients suffering from moderate to severe atopic dermatitis. The medications were applied to symmetrical, bilateral skin lesions twice daily for 4 weeks. Both treatments effected highly significant reductions of the score values for the severity of all clinical skin parameters assessed. Score reductions were, however, more pronounced on Locoid-treated sides than on Apolar-treated sides both after 2 and 4 weeks of therapy. It appeared further that clinical efficacy of treatment at completion of the study was also in favour of Locoid-treated sides, indicating that Locoid fatty cream is more effective than Apolar ointment. No serious side-effects were reported during the study. The expressed patient preferences with respect to cosmetic acceptability of treatments were significantly in favour of Locoid fatty cream, indicating that patients preferred the use of this new galenic formulation over an ointment formulation. It is concluded that the new application form of Locoid, a fatty cream, is a useful and beneficial addition to topical corticosteroid therapy, which will promote patient compliance in a wide range of corticosteroid-responsive skin diseases.