Background Although very little scientific data exists on the efficacy and side effects of complementary and alternative medicines, their profile and availability is increasing. Use among Irish children is unknown.Aims To determine the nature and prevalence of complementary and alternative medicines (CAM) use in our paediatric population.Methods Parental questionnaires were distributed in 13 paediatric settings over a 4-month period.Results There were 57% of parents reported using CAM for their child. Use was significantly higher in the 2-4 years age group (34/105, 32%, P = 0.005). The commonest medicinal CAMs used were vitamins (88%), fish oils (27%) and Echinacea (26%). The commonest non-medicinal CAMs used were homeopathy (16%) and craniosacral therapy (14%). Use varied between paediatric specialties, with the highest in neurological patients (23/25, 92%, P = 0.005). Only 13% of parents had informed their Paediatrician of their child's CAM use.Conclusions More than half of the children surveyed had used some form of CAM, usually without their Paediatrician's knowledge.