How to provide effective attitudinal learning in large-enrollment classrooms is a continuing question in higher education. This qualitative single case study investigated instructional design strategies and activities that could effectively be applied to attitude change in large-enrollment learning contexts. By evaluating an undergraduate sustainability course from multiple perspectives, this study focused on answering four research questions: (1) Did students perceive that their attitudes towards sustainability changed after taking the course? (2) From expert instructional designers' perspectives, to what extent was the course design aligned with the first principles for attitudinal instruction? (3) From both the instructor and students' perspectives, what instructional activities were most effective for attitude change? (4) From the instructor's perspective, what were the key instructional design strategies for promoting effective attitudinal instruction? Results showed that despite the challenges a large course might present, this course successfully helped students change their attitudes towards sustainability. A variety of instructional strategies and activities were applied in this course, including active learning, instructional videos, collaborative projects, and teamwork. This case study set a successful example of incorporating active learning strategies and activities in large classroom contexts.