Electronic books are a fast-growing component of the publishing industry. Sales of electronic textbooks (e-textbooks) are growing, but at a slower rate. In this research we use data from an undergraduate student survey to estimate the determinants of e-textbook use. We find that students who are younger, lower-income, and from larger high schools are more likely to use e-textbooks. E-textbooks are more likely to be used by students in the more technically-oriented colleges and especially in the college of Business and Economics, where electronic materials are often required. An environment of continued growth in student technical competence with information technology, continued increases in college cost and a reduction in professor resistance to e-textbooks would bode well for growth in the use of them. (Contains 3 tables and 6 footnotes.)