This study examines the differences in undergraduate library use by academic discipline at Oregon State University (OSU). In the winter of 2006, an online questionnaire about physical and virtual library use was distributed to 3,227 OSU undergraduates; 949 responses were received. Chi-square tests were used to distinguish differences between user groups. The results indicate that students in the Agricultural Sciences College use the physical library less than students in the Liberal Arts College, Health and Human Sciences College, and the Sciences College; students from the Engineering College use the virtual library less than students from the Liberal Arts College. (Contains 30 notes.)