We have investigated the impact of using multimedia learning modules (MLM) on the learning of students enrolled in introductory physics courses at California State Polytechnic University, Pomona. One hundred fifty-nine students were randomly registered in two sections of an introductory mechanics course, one of which featured the MLMs. Both sections had the same instructor, participated in class discussions on identical topics, and used the same problem-solving examples. The students in the multimedia group outperformed the students who did not experience the MLMs in a final course examination and across identical discussion questions. (Contains 3 figures and 3 tables.)