With additional features and increasing cost advantages, e-textbooks are becoming a viable alternative to paper textbooks. One important feature offered by enhanced e-textbooks (e-textbooks with interactive functionality) is the ability for instructors to annotate passages with additional insights. This paper describes a pilot study that examines the effects of instructor e-textbook annotations on student learning as measured by multiple-choice and open-ended test items. Fifty-two college students in a business course were randomly assigned either a paper or an electronic version of a textbook chapter. Results show that the e-textbook group outperformed the paper textbook group on the open-ended test item, while both groups performed equally on the multiple-choice subject test. These results suggest that the instructional affordances that an interactive e-textbook provides may lead to higher-level learning.