Non-steroidal anti-inflammatory drugs (NSAIDs) and opioids are commonly prescribed drugs which are frequently used for the treatment of various painful conditions. However, particularly for the paediatric population, there is a lack of information on effectiveness, safety and appropriate formulation resulting in off-label use and undertreatment. The aim of this study was to investigate the prescribing patterns of non-steroid anti-inflammatory drugs and opioids in children and adolescents in three European countries. A retrospective cohort study was conducted using the same protocol in three primary care databases: Pedianet (Italy), IPCI (Netherlands) and IMS Disease Analyzer (UK). User prevalence rates were calculated for opioids (N02A) and non-steroidal anti-inflammatory drugs (NSAIDs) (M01A) based on ATC therapeutic and chemical levels and stratified by country, age and gender. The prescribing prevalence for NSAIDs was lower in the Netherlands compared to Italy and the UK. Ibuprofen was the most frequently prescribed drug in this group in Italy (20.8 users/1000 PY) and the UK (30.6 users/1000 PY) whereas diclofenac was dominant in the Netherlands (1.7 users/1000 PY). Among opioids, codeine and codeine combinations were most commonly prescribed: only little use was seen for other drugs. There is a great variety of different NSAIDs and opioids prescribed to children in Europe in primary care. This is due to a varying availability of drugs in different countries but also because of differing prescribing attitudes, reimbursement scheme and a lack of data on the effectiveness of individual drugs. Further research into the rationale for prescribing these drugs to children is clearly needed. (C) 2010 Elsevier Ltd. All rights reserved.