Up to a few years ago the transdermal application of analgesics to treat chronic and tumour-induced pain only was possible within the limits of a local therapy. Thereby topically acting substances like local anaesthetics, non-steroidal antiphlogistics or capsaicin were used. Through the introduction of transdermal therapeutic systems (TTS) with opioids an efficient and reliable systemic opioid therapy with fentanyl was made possible in 1995, and also with transdermally applied buprenorphin in 2001. Not only because of the long application intervals and the simple administration the available systems represent a good alternative to the retarded, orally administered opioids on stable pain conditions with permanent opioid demand. With regard to the side effects, these systems only tend to have advantages compared to orally administered opioids.