An evaluation of Chesapeake Bay Foundation's environmental education programs provides context for this study exploring the role of student self-determination in service-learning. Research questions include (1) How do self-determination-related characteristics of service-learning programs affect students' attitudes toward service-learning (ASL), and (2) How do attitudes toward service-learning affect environmental education outcomes? Results demonstrate that one self-determination-related characteristic, service-learning graduation requirements, did not affect students' ASL. Other factors such as perceived student choice and participation in different service-learning programs, however, did impact ASL. Furthermore, ASL was strongly related to outcomes including environmental sensitivity, personal responsibility and intentions to help the environment.