OBJECTIVE: To determine the prevalence of and reasons for the use of complementary and alternative medicine (CAM) in paediatric patients, and to determine the parental need for appropriate information from their paediatrician. DESIGN: Questionnaire. METHOD: A questionnaire was given to the parents of general paediatric patients of the St. Antonius Hospital Nieuwegein and the University Medical Centre Utrecht, the Netherlands, in the period June 2003-March 2004. Parents were asked about CAM use in the past 12 months, which CAM modalities were used and their reasons for using it. They were also asked about their need to receive information on CAM from their paediatrician. RESULTS: A total of 581 of 617 parents completed the questionnaire (94%). CAM was used by 177 (30%) patients. The most frequently used types of CAM were homeopathy (48%), phytotherapy (45%), nutritional supplements (28%) and manual therapies (28%). CAM was used most often in children with headache or chronic fatigue. The most frequently cited reasons for CAM use were a desire for the child to feel better and a preference for a 'more natural' therapy. Factors associated with CAM use were a high level of parental education and use of CAM by the parent. Only 40% of parents had reported the use of CAM to their paediatrician, usually on their own initiative. The majority of the parents (60%) found it important to very important that the paediatrician is able to provide information on CAM. CONCLUSION: Almost one-third of patients visiting a general paediatrician had used complementary or alternative medicine in the past year. Given the possible interactions with conventional therapies and the desire of parents to receive more information on CAM, paediatricians should expand the patient history assessment to include questions regarding the use of CAM.