Complementary medicine (CM) is more popular than ever before. Dermatology has not remained unaffected by this trend. The aim of this systematic review was to summarize all surveys of dermatological patients regarding the usage of CM. Three independent literature searches were carried out. Data were extracted in a predefined, standardized way and evaluated descriptively. Seven surveys met the inclusion/exclusion criteria. Collectively they show a high but variable prevalence of CM. Lifetime prevalence ranged from 35 to 69%. The most frequently used treatment modalities comprise homoeopathy, herbalism and food supplements. With this high level of prevalence, research into the potential risks and benefits of CM is urgently needed. Dermatologists should consider discussing CM openly with their patients.