Given the upsurge of textbook costs, college students increasingly expect universities and instructors to offer alternatives to traditional textbooks. One textbook alternative is using open educational resources (OER). While OER unquestionably save students money, the question remains whether the adoption of OER (instructional materials) is aligned with open pedagogy (methods). This study investigated 46 undergraduate students' perceptions of using only OER in an introductory course in a large American public university. As reported by study participants, advantages of using OER include textbook cost savings, access to dynamic and plentiful OER materials, that OER enabling mobile learning, and that OER foster the development of self-directed skills and copyright guidelines. Challenges reported include lacking a tactile sense with OER, slow Internet connections, unclear instruction and guidance, and insufficient self-regulation skills. Course design and implementation considerations were discussed.