Although higher education has spent millions of dollars on instructional technologies, often higher education administration complains that instructors are not adopting them. Without a full understanding of possible barriers, higher education institutes are hard-pressed to develop either appropriate goals or sound strategies for the adoption of instructional technology. A review of the literature on barriers to instructor adoption found conflicting results, in which some issues present more of a barrier than others. These range from a lack of definition of successful adoption (how many adopting instructors are enough?) to inadequate or inappropriate professional development (meeting differing instructors' needs) to resistance (based on self-efficacy, beliefs in pedagogy, etc.). Five categories are described based on literature researched: technology, process, administration, environment, and faculty. Within each of these categories is a description, based on the literature, of each barrier. A fish-bone diagram displaying the categories and barriers within them is presented. This review of the literature provides a framework for further research in methods for minimizing the impact of each barrier. The framework of categories of barriers presented here provides institutions with a starting point to approach adoption of instructional technology with a plan to mitigate and minimize as many barriers as possible, giving adoption a better chance of success.