On October 15 and 16, 1990, a workshop on the subject of plasmasphere refilling was held at The University Alabama in Huntsville. N. Singh and J. L. Horwitz were the convenors of this workshop. Approximately 35 participants attended 24 oral presentations, including scientists from the United States, Hungary, Soviet Union, France, Belgium, and Canada. Observational areas covered in these presentations included measurements of plasmaspheric density distributions and dynamics, flows and detailed particle distribution functions, and wave properties. Theoretical topics included kinetic and hydrodynamic descriptions of the refilling of isolated flux tubes, global modeling of convection and large-scale plasmasphere refilling, and wave-particle interactions. There was also considerable discussion of some of the controversial areas of the subject. The plasmasphere refilling region, or outer plasmasphere region, is a unique region in the magnetosphere in that the basic boundary conditions, such as the magnetic field geometry and approximately the nature and rate of the plasma influx, are fairly well known, and yet many fascinating phenomena, including colliding streams, hot-cold plasma interactions and shocks, are thought to play important roles in the refilling process. Therefore it is a region of the magnetosphere where the physics can be extremely interesting and yet seems closer to tractability than in other magnetospheric regions which come to mind. Some of these areas are explored in the papers which appear in the special section. ¿ American Geophysical Union 1992