This article describes and assesses the effectiveness of a 3-yr, laboratory-based summer science program to improve the academic performance of inner-city high school students. The program was designed to gradually introduce such students to increasingly more rigorous laboratory experiences in an attempt to interest them in and model what "real" science is like. The students are also exposed to scientific seminars and university tours as well as English and mathematics workshops designed to help them analyze their laboratory data and prepare for their closing ceremony presentations. Qualitative and quantitative analysis of student performance in these programs indicates that participants not only learn the vocabulary, facts, and concepts of science, but also develop a better appreciation of what it is like to be a "real" scientist. In addition, the college-bound 3-yr graduates of this program appear to be better prepared to successfully academically compete with graduates of other high schools; they also report learning useful job-related life skills. Finally, the critical conceptual components of this program are discussed so that science educators interested in using this model can modify it to fit the individual resources and strengths of their particular setting. (Contains 3 figures and 6 tables.)