BACKGROUND: Despite the important role of drug therapy in children, there is often a lack of readily available information regarding the indications and dosing regimens for medications in paediatrics. OBJECTIVE: To collect data on where family physicians obtain this prescribing information. METHOD: A structured questionnaire was mailed to 500 family physicians in Ontario. RESULTS: Questionnaires were returned by 261 (52%) family physicians, 217 (83%) of whom identified themselves as currently involved in the care of children. Most (87%) reported that the Compendium of Pharmaceuticals and Specialties (CPS) was the source that they most commonly consulted for drug information in children. The available sources of information on prescribing for children were thought to be not adequate by 40% and not readily available by 27%. Sixty-one per cent reported being moderately confident (in doubt part of the time) about their decisions regarding drug prescribing in this age group. The majority (70%) had learned most of what they know about prescribing in paediatrics during practice, while 69% and 62% reported they had little or no teaching during undergraduate and postgraduate (internship or residency) medical education, respectively. CONCLUSIONS: Although it is recognized that for a number of drugs used in children the CPS does not reflect the current standard of care in paediatrics, it is currently the source most commonly referred to by family physicians. Further work should be done in the provision of useful information on paediatric drug therapy to family physicians.