BACKGROUND: Insight into referral patterns provides general practitioners (GPs) and specialists with a frame of reference for their own work and enables assessment of the need for secondary care. Only approximate information is available. AIM: To determine how often, to which specialties and for what conditions children in different age groups are referred, as well as how often a condition is referred given the incidence in general practice. METHOD: From data of the Dutch National Survey of Morbidity and Interventions in General Practice, 63,753 new referrals (acute and non-acute) were analysed for children (0-14 years) from 103 participating practices (161 GPs) who registered. Practices were divided into four groups. Each group of practices participated for three consecutive months covering a whole year altogether. We calculated referral rates per 1000 children per year and referability rates per 100 episodes, which quantifies the a priori chance of a condition being referred for specialist care. RESULTS: The referral rate varied by age from 231 for children under 1 year old to 119 for those aged 10-14 years (mean 159). The specialties mainly involved were ENT, paediatrics, surgery, ophthalmology, dermatology and orthopaedics. Referrals in the first year of life were most frequently to paediatricians (123); among older children the referral rate to paediatricians decreased (mean 36). Referrals to ENT specialists were seen particularly in the age groups 1-4 (71) and 5-9 (53). For surgery, the referral rate increased by age from 19 to 34. Differences between boys and girls were small, except for surgery. The highest referral rates were for problems in the International Classification of Primary Care (ICPC) chapters: respiratory (28); musculoskeletal (25); ear (24) and eye (21). Referability rates were, in general, low for conditions referred to paediatrics and dermatology and high for surgery and ophthalmology. The variation in problems presented to each specialty is indicated by the proportion of all referrals constituted by the 10 most frequently referred diagnoses: from 35% for paediatrics to 81% for ENT; for ophthalmology, five diagnoses accounted for 83% of all referrals. CONCLUSIONS: The need for specialist care in childhood is clarified with detailed information for different age categories, specialties involved and variation in morbidity presented to specialists, as well as the proneness of conditions to be referred