Physics laboratories are intended to provide students an opportunity to investigate physical phenomena by making observations, collecting and analyzing data, and presenting their findings clearly. However, some students lack an adequate preparation and conceptual background to achieve these objectives. To help students to better prepare for the laboratory sessions at Cal Poly Pomona, in a pilot study, we designed a 20-minute online multimedia prelab tutorial on the topics of conservation laws using flash animations, narration, and videos. This multimedia prelab includes a brief lesson on the theory, as well as an introduction to the laboratory procedure and apparatus with embedded assessment questions and feedback throughout the module. The preliminary data shows improvement in student overall preparation, quiz scores, and their lab reports after using this prelab tutorial.