The present research investigated how personal beliefs about homosexuality influence learning in a college course. We tested students in introductory psychology over material on the science of homosexuality by Simon LeVay (2010). All students reported information about their typical academic habits and the extent to which homosexuality was consistent with their beliefs and values. The results showed that students' personal beliefs were related to academic behaviors (e.g., reading assignments, skipping class) and retention of the course material. The results also showed that students' recall of course material six weeks later was predicted by the extent to which they reported studying information that is inconsistent with their beliefs for an exam and then forgetting it. Students who reported the material to be inconsistent with their beliefs engaged in selective forgetting of the material on homosexuality. The results provide evidence that personal beliefs can reduce the retention of belief-inconsistent information in a college course.