Purpose To report the findings of a study that evaluated the impact of three youth-friendly service (YFS) projects in Lusaka, Zambia. In 1994, the Lusaka District Health Management Team (LDHMT) identified adolescents as a priority underserved population with regard to reproductive health information and services. As part of its long-term goal to improve the health and well-being of Lusaka youth, the LDHMT, in collaboration with CARE, UNICEF/Zambia Family Life Movement, and John Snow International, implemented three separate YFS projects to increase service use among adolescents. Methods Service statistics from 10 clinics (8 “treatment clinics” and 2 “non-YFS clinics”) were used to measure adolescent service use. Qualitative and quantitative data were collected to measure the degree of “youth-friendliness” at the clinics and the level of community acceptance of providing reproductive health services to youth. Specific indicators of youth-friendliness were developed that measured the attitudes of the clinic staff toward giving services to youth, whether clinic staff honored privacy and confidentiality, whether boys and young men were welcomed, whether the clinic policies supported providing services for youth, whether clinic staff promoted its services to youth in surrounding community, and whether youth, themselves, perceived that they would be welcomed and have their needs met at the clinics. Similarly, indicators of community acceptance were developed that measured whether parents and other adults supported the provision of reproductive health services to youth. Results and conclusions Although the projects appear to have improved the clinic experience for adolescent clients and to have increased service use levels at some clinics, the findings suggest that community acceptance of reproductive health services for youth may have a larger impact on the health-seeking behaviors of adolescents.