Research has long suggested that an optimal level of involvement in academic and social activities positively affects student development and outcomes. However, many second-year students experience the "sophomore slump." For this study, guided by both prior literature and theoretical perspectives, a survey instrument was developed to measure students' participation and involvement in a range of academic and social activities. The dependent variables comprised of five scales representing various aspects of involvement. Independent variables included student background characteristics, environmental variables, and psychological measures. Results from regression analyses indicate that academic self-efficacy and institutional commitment were strong predictors of sophomore involvement. Student background characteristics illustrate differences in the degree to which students were involved. Living on campus was positively related to sophomore involvement. A discussion of implications for practice follows.