To assess the impact of a college preparation program, district-wide changes in high-stakes test pass rates are examined, followed by an examination of specific program elements that are associated with students' score changes. Changes in pass rates for districts with and without services are compared for the Latina/o and overall student populations. This study also examines the relationship between hours of participation in various elements of the college preparation program and changes in test scores of low-income Latina/o students. Results indicate that key program elements related to improvements in test scores include participation in mentoring and summer programs.