Computerized procedures have been developed for calculating ocean sediment accumulation rates in terms of mass per unit area. Using these procedures and a simplified plate tectonic model, palinspastic maps of sedimentation in the Pacific Ocean over the past 48 million years (m.y.) have been prepared. These maps show a relatively simple and persistent sedimentation pattern with maximum accumulation occurring around the perimeter of the ocean and along the equator. Sediment seems to be more uniformly distributed at times of low overall accumulation rates. The maps further show that the history of sedimentation in the Pacific over the past 48 m.y. can be divided into five broad time periods: 0-6 m.y., 6-15 m.y., 15-27 m.y., 27-42 m.y., and prior to 42 m.y. Detailed differences between the sediment accumulation patterns of these time periods are related to major reorganizations of Pacific Ocean circulation and climate.