Purpose: The purpose of this paper is to describe the process and lessons learned from an evaluation of "Teen Talk", a health drop in service at Kidbrooke, a state secondary school in Greenwich. Design/methodology/approach: A multi-pronged approach was adopted for the evaluation. This included a questionnaire survey of a sample of 180 pupils within the school; in-depth discussions with 12 young people who had used the service; interviews with health and education professionals and parents; desk research including an analysis of costs and discussions with senior staff in other schools in Greenwich to determine the feasibility of replicating the "Teen Talk" model elsewhere in the borough. Findings: "Teen Talk" is greatly valued by pupils and staff at the Kidbrooke and was seen to provide a unique service. The overall perception is that it provides good value for money. However, the evaluation identified important lessons in setting up and managing the project which can help refine the service and which have relevance for local and national contexts. Research limitations/implications: This paper illustrates the advantages of embedding evaluation research in health service design and implementation, particularly when there is the potential of replicating service delivery models in other school settings. Originality/value: Creating safe and confidential spaces for young people to access help and advice on a range of health issues is by now well recognized as good practice. School-based health facilities are a relatively new approach to young people's health promotion. Although the benefits of this type of provision are largely undisputed, to date, few such services have been evaluated. (Contains 6 tables.)