Summary Poor adherence with therapy is a major cause of treatment failure in atopic dermatitis. Reasons given are multifactorial, and include fear of real or imaginary side-effects, under-prescribing, failure to renew prescriptions on time, lack of time, and child refusal of therapy. Most important, however, is lack of knowledge about treatment, in particular the use of topical corticosteroid (TCS) therapy. We conducted a questionnaire-based study to determine the level of use and knowledge of commonly prescribed TCS preparations amongst parents or carers of 100 children attending paediatric outpatient clinics. Weakly potent TCSs were the most commonly used (86%), but poorly understood. Only 35 (41%) who had used hydrocortisone were aware that it was weakly potent, and 44% graded it as moderately potent. Of 65 who had used the moderately potent TCS clobetasone butyrate 0.05% (Eumovate®; Glaxo Wellcome, Uxbridge, UK), 19 (29%) graded it as potent and eight (12%) as weak. Of 50 who had used betamethasone valerate 0.1% (Betnovate®; Glaxo Wellcome, Uxbridge, UK), 42% did not grade it as potent. Understanding of TCS/antimicrobial combinations was generally worse. The hydrocortisone 1%/fusidic acid 2% combination (Fucidin H®; Leo, Risborough, Bucks, UK) was graded as moderate or strong by 88% of the 74 who had used it. Over half (53%) of the 34 using the combination of clobetasone butyrate 0.05%/nystatin 100 000 i.u./g tetracycline 3% (Trimovate®; Glaxo Wellcome, Uxbridge, UK) assumed that it was a potent TCS. Forty-nine had used Fucibet® (betamethasone valerate 0.1%, fusidic acid 2%; Leo, Risborough, Bucks, UK) but 34.5% did not grade it as potent. There was poor knowledge of the strengths of some of the most commonly used TCSs, and all steroid/antimicrobial combinations were perceived as being of greater potency than the constituent steroid alone. Fusidic acid was thought to be a steroid by almost half (46.9%) of the respondents. The packaging of the different products by some pharmaceutical companies is remarkably similar and labelling contains information on the compound and percentage rather than potency of the TCS. This may be a source of confusion. We recommend that manufacturers clearly label TCS products by potency as mild, moderate, potent or very potent and that packaging is sufficiently different for each strength of TCS or emollient to avoid confusion. In order to achieve optimal topical treatment for atopic dermatitis, patients and their carers must receive adequate information and training in how and when to use topical therapies in conjunction with written care plans.