Objective: The aim of the present study was to investigate the relationship between area-level socio-economic status and healthy and less healthy eating behaviours among adolescents and to determine whether the relationship between area-level socio-economic status and dietary behaviours was related to the relevant attitudes and environments. Design: Data were collected as part of Youth'07, a nationally representative survey of the health and well-being of New Zealand youth. Setting: New Zealand secondary schools, 2007. Subjects: A total of 9107 secondary-school students in New Zealand. Results: Students from more deprived areas perceived more supportive school environments and cared as much about healthy eating as students in more affluent areas. However, these students were significantly more likely to report consuming fast food, soft drinks and chocolates. Conclusions: Addressing area-level socio-economic disparities in healthy eating requires addressing the availability, affordability and marketing of unhealthy snack foods, particularly in economically deprived areas.