While age estimation of unidentified corpses and skeletons for identification purposes has a long tradition in forensic sciences, age estimation of living persons has formed a relatively recent area of forensic research which is becoming increasingly important. The international interdisciplinary Study Group on Forensic Age Diagnostics (AGFAD) issued recommendations for age estimation of living persons for the purpose of criminal, civil, asylum and old-age pension procedures as well as for determining the sex and age of skeletons. In the present work, the authors set out state-of-the art age estimation methods for specific case groups, define minimum requirements for reference studies and specify the need for further research. In addition, ethical and medico-legal aspects as well as issues relating to quality assurance are discussed.