Using cross-classified multilevel modeling, this study attempted to improve our understanding of the group-level conditional effects of student-faculty interaction by examining the function of academic majors in explaining the effects of student-faculty interaction on students' academic self-concept. The study utilized data on 11,202 undergraduate students who completed both the 2003 Freshman Survey and the 2007 College Senior Survey at 95 baccalaureate institutions nationwide. The results show that the strength of the relationship between having been a guest in a professor's home and students' academic self-concept varies by academic major. Findings also suggest that some aspects of departmental climate, such as a racially more diverse student body and greater faculty accessibility, can possibly magnify the beneficial effects of student-faculty interaction. The study discusses the theoretical and practical implications of the findings.