This paper discusses the results of a study that examined the mental health needs of 796 adolescents who interacted with four types of service sectors that typically function as gateways to mental health services (education, child welfare, juvenile justice, and primary health). Prevalence estimates collected from the youth themselves were compared to counts of clients kept by the gateway providers and comments made in focus groups by these providers regarding their understanding of mental health service issues. Interviews with the youth indicated that significant numbers of youth at each of the four sectors had mental health problems. However, only a limited percentage of those youth with mental health problems received services from their gateway sector. This percentage varied widely by sector, with the juvenile justice, education, and child welfare sectors providing services to a much higher percentage of youth than the health sector. The education sector had a very large discrepancy between the youth's interview data and the providers' tally data, although many of the youth with mental health problems felt they were receiving help. (CR)