The research potential of many UK clinical databases is not being realized. A recent report published by the Royal College of Paediatrics & Child Health stated that there is a need to build research capacity and support in the area of paediatric pharmacology, with specific emphasis on the use of clinical databases. This article presents the databases available in the UK for medication research and gives some examples of paediatric studies conducted. The databases discussed include the Prescription Pricing Authority database, the General Practice Research Database, IMS Health databases (Medical Data Index, MIDAS Prescribing Insights, Disease-Analyser-Mediplus) and the Yellow Card Scheme. Other databases such as the Medicines Monitoring Unit (MEMO) and the Scottish Primary Care Computer System also have research potential in paediatric pharmacoepidemiology, but their population sizes are relatively small.