Companies produce increasing numbers of textbooks in electronic format (e-textbooks) for use by students and instructors. One would be remiss, however, to think that university bookstores are not filled with hard copies of textbooks; many students and instructors still insist on using traditional paper copy textbooks. Many models exist to explain the factors that influence whether users adopt new technologies. The majority of this research, however, focuses on a single user group or isolated new technologies in the academic domain, such as learning management systems or digital video tools. The study extends the Task-Technology Fit (TTF) model to explore how both students and instructors use e-textbooks. New items were added to existing constructs of access, task technology fit, and perceived ease of use. The authors propose a new model and test the impact of perceived ease of use, access to technology, and the task technology fit on performance by both students and instructors. The results of factor analysis and structural equation modeling are reported.