The few studies focusing on the relationships between higher education expenditures and student outcomes have produced contradictory results. This study hypothesized that the lack of consistent relationships is a function of the fact that the effects of expenditures on outcomes are mediated by student engagement. Furthermore, it is expected that the relationships between expenditures and outcomes are contingent on the characteristics of the students and institutions being studied. The present research examined the relationships between higher education expenditures and students' engagement in educationally purposeful activities, after controlling for a variety of student and institutional characteristics. Using data from a nationally representative sample of colleges and universities, the findings indicated that the relationships between expenditures and student engagement are very complex. Relationships differed by institutional control, students' year in school, and the type of engagement measure included in the analysis.