This study compared the perspectives of foreign and Japanese instructors regarding the impact of the former on lesson content and student learning. Participants consisted of 208 Assistant Language Teachers (ALT) and 96 Japanese Language Teachers (JLT) working together through the Japan Exchange and Teaching (JET) Program. Path models constructed to illustrate causal relationships among eleven selected variables revealed three findings: (a) Both groups observe a close interdependency between ALT motivation and student learning; (b) ALTs stress the educational benefit of non-duty related interaction with both staff and students, while JLTs emphasize the integration of foreign instructors in school life; and (c) JLTs are more likely than ALTs to perceive a relationship between the nature of team-taught lesson content and student learning. (Contains 2 figures and 2 tables.)