Low energy positron annihilation measurements have been used widely in solid state physics, materials science, atomic and molecular physics and chemistry, radiation chemistry, and medicine. This Conference marked the fiftieth anniversary of the discovery of the positron by Carl Anderson, and the Opening Address was delivered by Professor Martin Deutsch of M.I.T., who discovered positronium about thirty years ago. Thirty one invited papers were presented covering all fields in which positron annihilation is used. 270 contributed papers were presented in oral and poster sessions. Of particular interest at this, the sixth conference in this series, was the emergence of monoenergetic positron beams as important tools in the study of fundamental processes and of the surface properties of materials.