BACKGROUND: Little is known about where teenagers and young adults receive their first cancer treatment. METHOD: We extracted data on 2260 residents of southeast England diagnosed with a malignant neoplasm aged 10-24 between 1998 and 2002 from the Thames Cancer Registry database. We identified 11 cancer network areas of residence, and the hospital and network where each patient received their first chemotherapy treatment. We classified hospitals as those including paediatric oncology centres, cancer centres with a teenage cancer unit or adult cancer centres or units. We examined how many patients in each of the age groups 10-14, 15-19 and 20-24 travelled outside their network of residence for chemotherapy. RESULTS: Overall 45% (1018) received chemotherapy. Three networks had paediatric oncology centres, and one also had a teenage cancer unit. Most 10-14-year-olds were referred from their network of residence to networks with these services. However, there was an increasing tendency for patients aged 15-19 and 20-24 to be treated within their network of residence and to be referred less commonly. CONCLUSIONS: Many young people with cancer are not referred to services providing care tailored to the needs of their age group. The absence of any pattern to referral, despite the presence of a teenage cancer unit in the area, suggests a lack of coordinated referral practice within and between cancer networks.