This paper summarizes the results of the first three years of an integrated on-site school health demonstration project based on the family practice model of delivering primary health care. An inner city public elementary school was chosen as the study location. Of the 712 study participants, 98% were black or Hispanic. Prior to implementation of the demonstration project, the Health Guarded Index for the study population was computed to be 58%. Among study participants, this index rose to 79% during the first year of the project and eventually reached 95% during the third year of the project. The absentee rates among study participants relative to nonparticipants decreased to 8.7% during the first year of the project and by 36.2% during the third year of the project. The substantial increase in the Health Guarded Index indicates that, among study participants, preventable defects, such as lack of immunizations, dental care, screening for common problems, and follow-up had been largely corrected. The substantial decline in absenteeism among study participants clearly shows the effectiveness of the demonstration project in promoting good health by decreasing morbidity and/or decreasing recovery time. Overall, the results of the three-year demonstration project reported here show that a carefully designed, well-coordinated school health program based on a family practice model can have a substantially favorable impact on the health of participating children.