The benefits of student engagement in diversity experiences on a range of college outcomes have been well documented. However, the potential influence of involvement in diversity experiences during college on the cognitive and intellectual outcomes of post-secondary education is only beginning to be understood. Gurin et al. (2002) made a convincing argument for why exposure to diversity experiences might foster the development of more complex forms of thought, including the ability to think critically. The present study sought to determine if the effects of exposure to diversity experiences on critical thinking skills extended beyond the first year of college and if these effects were detectable after 4 years of postsecondary education.