Monitoring the safety of medicine use in children is of paramount importance since during the clinical development of medicines only limited data on this aspect are generated through clinical trials. Use of medicines outside the specifications described in the license (e.g. in terms of formulation indications contraindications or age) constitutes off-label and off-license use and these are a major area of concern. These guidelines are intended to improve awareness of medicine safety issues among everyone who has an interest in the safety of medicines in children and to provide guidance on effective systems for monitoring medicine safety in pediatric populations. This book will be of interest to all health care professionals medicine regulatory authorities pharmacovigilance centres academia the pharmaceutical industry and policy-makers. Systems for monitoring medicine safety are described in Annex 1. Pharmacovigilance methods and some examples of recent information on adverse reactions to marketed medicines are discussed in Annex 2.