Guidelines on Good Publication Practice (GPP) for pharmaceutical companies are presented. The aim of the guidelines is to ensure that clinical trials sponsored by pharmaceutical companies are published in a responsible and ethical manner. The guidelines cover companies' responsibility to an endeavour to publish results of all studies, companies' relations with investigators, measures to prevent redundant or premature publication, methods to improve trial identification and the role of professional medical writers. Our aim in publishing the GPP guidelines, which are the first to be developed by and for those working on publications in the pharmaceutical industry, is to stimulate discussion between journals, investigators and trial sponsors and to provide guidance to those who seek it. We also hope that pharmaceutical companies and others involved in developing publications arising from sponsored clinical trials will endorse the guidelines.