Background: Long-term data of ciclosporin A (CsA) treatment in daily practice in patients with severe atopic dermatitis (AD) are lacking., Objectives: To perform a detailed analysis of drug survival, which is the length of time a patient continues to take a drug, for CsA in a long-term daily practice cohort of patients with AD. The secondary objective was to identify determinants of drug survival., Methods: Data were extracted from a retrospective cohort of patients treated with CsA for AD. Drug survival was analysed using Kaplan-Meier survival curves. Determinants of drug survival were analysed using uni- and multivariate Cox regression analyses with backward selection., Results: In total, 356 adult patients were analysed (386 patient-years). The overall drug survival rates were 34%, 18%, 12% and 4% after 1, 2, 3 and 6 years, respectively. Reasons for discontinuation were controlled AD (26·4%), side-effects (22·2%), ineffectiveness (16·3%), side-effects plus ineffectiveness (6·2%) or other reasons (11·0%). Older age was associated with a decreased drug survival related to controlled AD [hazard ratio (HR) 0·91]. Older age was also associated with a decreased drug survival related to side-effects (HR 1·14). An intermediate-to-high starting dose (> 3·5-5·0 mg kg(-1) daily) was associated with an increased drug survival related to ineffectiveness (HR 0·63)., Conclusions: This is the first study on drug survival for CsA treatment in AD. Older age was associated with decreased drug survival related to controlled AD and side-effects. An intermediate-to-high starting dose was associated with an increased drug survival related to ineffectiveness., (© 2015 British Association of Dermatologists.)