For the past 5 years I have been teaching my introductory geology class using a case-based method that promotes student engagement and inquiry. This article presents an explanation of how a case-based curriculum differs from a more traditional approach to the material. It also presents a statistical analysis of several years' worth of student assessment data from both the traditional and case-based curricula. These analyses demonstrate that the case-based method not only improves student learning relative to a traditional curriculum, it also improves students' ability to apply higher-order thinking skills to the study of the earth.