Background: Growth impairment during childhood and adolescence is a common problem faced by patients with an early onset of Crohn's disease. Aims: To establish how the final adult height is affected in patients with early onset of symptoms of Crohn's disease. Methods: Information on height, parental height, and disease history was obtained from 135 patients with Crohn's disease who reached their adult height (men 22-40 years, women 18-40 years) using a questionnaire and by outpatient measurement of height where possible. Subsequently, adult heights were expressed as standard deviation scores, with and without correction for the expected target height. Results: Patients with onset of disease before puberty were shorter compared with patients with onset in adulthood (p