Educational institutions face unrelenting pressure to incorporate the latest technology into their classrooms. U.S. higher education has been adopting computers to augment the in-class learning experience. Anecdotally, computers (PC and Mac architectures) and tablet devices (iPads, smartphones, and tablet PCs) have been used in a myriad of settings for interactive polling as means to increase student participation and engagement. To date, other uses of computers and tablet devices have taken hold in project-focused or problem solving-oriented small classes rather than in large lecture classes. Undergraduate mathematics classes seem to be a natural fit for introducing tablet devices as many students find it easier to handwrite mathematical notation than to use a keyboard. This study investigates the impact of a tablet PC implementation in undergraduate college algebra and trigonometry (CAT) on student performance and retention in science, technology, engineering, and mathematics (STEM) majors. This longitudinal project explores the effect of Tablet PC use in an important gateway course for freshmen who intend to major in a STEM field. Five important metrics were assessed: class attendance, class performance, instructor evaluation, retention in STEM, and persistence to graduation. The CAT course was taught by the same instructor as a conventional CAT lecture class from 2005 to 2007 using the same textbook, secure exams, and grading rubric. This structure provides a reasonably well-controlled setting in which to assess the impact of tablet PCs on retention in STEM.