In two experiments, we examined the benefits of cumulative and noncumulative finals on students' short- and long-term course material retention. In Experiment 1, we examined results from course content exams administered immediately after course finals. Course sections including cumulative finals had higher content exam scores than sections with noncumulative finals. In Experiment 2, current and former students completed online versions of content exams up to 18 months after course completion. Students completing courses with cumulative finals retained more than students who took noncumulative finals. Introductory psychology students benefited more from cumulative finals than did upper-division course students. Based on our results, we suggest that instructors use cumulative finals to increase short- and long-term retention of course material. (Contains 1 note and 3 tables.)