Authorship of publications has been the subject of much public debate; however, authorship of clinical trial documents such as clinical study protocols, clinical study reports, investigator’s brochures and inform ed consent forms has not really been given much attention. This article looks at the common practices of authorship attribution and signing off on these documents and examines what the ICH guidelines, on which their contents are based, say about these issues. The implications of the EMA Policy 0070 on clinical trial disclosure are discussed.