To address the need for greater flexibility in access to higher education, an online graduate course in physiology using case studies was developed and offered in summer 2012. Topics in both animal and human physiology were organized as modules that contained a case study with questions, a prerecorded online lecture, and three research journal articles. We followed best practices for teaching and learning in distance education, including the preparation of materials before the course starting date, a discussion board for responding to pre- and postcase discussion questions, and prompt reply to student queries. For exams, students generated their own questions based on new cases and developed their own case study for the final project. Although only 20% of students had previously taken an online course, all students stated that they would recommend this course to others. Postcase assessment indicated that students found the cases interesting, informative, and presented at the appropriate level. Most students said that the online course took them more time but that they learned more content and used the primary literature more than in a traditional class. Our results indicate that a well-organized physiology course using a case study format is a very effective model for online learning. (Contains 5 tables.)