At Georgia Southern University (GSU), a regional university of 17,000 students, environmental science is a required introductory course for all students. Consequently, environmental-biology class sizes are large, often approaching 1,000 students each semester in multiple sections of up to 250 students. To improve students' learning and sense of environmental responsibility, the authors developed a service-learning component of the course. Nearly all students participated and their responses were overwhelmingly positive. This type of learning shows students the relevance of content conveyed in the classroom and that they can make a difference in their community. (Contains 2 tables and 1 figure.)