Acute generalized exanthematous pustulosis (AGEP) is a rare disorder, usually drug-induced, and is clinically characterized by widespread, non-follicular aseptic pustules. Although spontaneous resolution usually occurs once the causative drug has been withdrawn, more severe cases often require treatment with systemic corticosteroids. We report a 63-year-old woman who developed AGEP after a 30-day course of hydroxychloroquine. Extensive re-exacerbation of AGEP after an 18-day course of methylprednisolone led us to switch the treatment to oral ciclosporin with a prompt and satisfactory improvement. Ciclosporin has many inhibitory effects on the main cell population (T cells) involved in AGEP. In particular, a significant reduction in production of interleukin-8 by T cells is a possible explanation of the rapid remission observed in this case. To our knowledge, this is the first reported case of AGEP successfully treated with ciclosporin.