To guide the development of adolescent health training and the planning of future services, accurate data describing health service use by adolescents and young adults are needed.Aim: To describe admission rates for adolescents (12–17 years) and young adults (age 18 years and over) attending a specialist children's hospital over an 8-year period. Specific objectives were to describe the (i) proportion of adolescents and young adults admitted under different specialties; (ii) age range, with emphasis on those 18 years and over; and (iii) proportion of patients admitted to the general adolescent ward.Methods: Data on adolescent and young adult admissions to Princess Margaret Hospital (PMH) were collected prospectively from July 2000 to June 2008.Results: Adolescents and young adults accounted for one fifth (range 18–22%) of all admissions to PMH. Over the 8-year period, the number of adolescent and young adult admissions increased from 3935 (54% males) to 4967 (56% males) per year. The proportion admitted to the general adolescent ward ranged from 22% to 36%. The three specialties admitting the most adolescents and young adults were General Surgery (11–13%), Orthopaedics (11–13%) and Oncology/Haematology (10–14%). The age range was: 12–14 years (57–67%); 15–17 (30–39%); 18+ (2–5%). At least 15 patients aged 20 or over were admitted each year, mostly for Dental or Plastic Surgery.Conclusions: Adolescent and young adult health is part of the core business of paediatrics. This should be reflected in the planning of future paediatric services. All trainees require some basic training, regardless of heir specialty area.