The Office of Naval Research (ONR) funds research across a broad range of scientific and engineering disciplines in support of the Navy and Marine Corps. To ensure that its investments are serving those ends and are of high quality, ONR requires each of its departments to undergo annual review. Since 1999, the Naval Expeditionary Warfare Department of ONR has requested that the NRC conduct these reviews. This report presents the results of the second review of the Marine Corps Science and Technology program. The first review was conducted in 2000. The 2003 assessment examines the overall Marine Corps S&T program, the littoral combat future naval capability, the core thrusts of the program, and basic research activities.