This study identified the physical demands of U.S. Navy Sea-Air-Land (SEAL) operations. SEALs were interviewed regarding missions conducted and an inventory of missions and mission segments performed was developed. Questionnaires were developed from the inventories once they were judged comprehensive and accurate. SEALs rated each task on difficulty, frequency performed, and importance to mission success. For each task, scores were summed to obtain a 'composite' score. The composite score mitigated the effect of difficult tasks that were less important or infrequently performed when missions and segments were compared. Eighty-two SEALs averaging 11 years of experience (range 2-28 years) participated. Of the 15 missions rated highest on the composite score, 6 were 'overland', 5 were 'across the beach,' and 4 were 'ship attacks.' The highest ranking mission had been performed by 85% of the SEALs, and 8 (of the 15 highest) missions had been performed by >50%. Of the 20 highest rated mission segments, 9 involved 'lifting/dragging/carrying/climbing,' 6 involved 'walking/hiking/skiing,' 3 involved 'swimming/diving,' and 2 involved 'jumping/bumping.' The highest ranking mission segment had been performed by 90% of the SEALs and over 50% performed 18 of the 20 most important mission segments. These data will provide a basis for the development of mission-specific physical training programs.