This study investigates the experience of student engagement in high school classrooms – both the influences on engagement as well as the short-term and long-term educational outcomes resulting from engagement. The experiences of 526 tenth and twelfth grade students enrolled in 13 U.S. high schools during the 1990s were examined. Data were gathered using the Experience Sampling Method (ESM) and student interviews. Students reported higher engagement during individual and group work than while listening to the teacher lecture, watching a video, or taking a test – and also during their non-academic classes such as art, computer science and vocational education compared to their traditional academic classes. Engagement also predicted long-term continuing motivation and college performance. Over all, results suggested that activities and classrooms that combined academic intensity with features that provoke a positive emotional response are more likely to engage students the short term and the long term.