The application of analytical ultracentrifugation (AUC) to solve problems of colloid chemistry seems to have been almost forgotten ever since the pioneering experiments of Svedberg and co-workers in the 1920s. Although AUC was initially developed as a technique to study particle size distributions of gold colloids, it rapidly showed its versatile character with the experimental proof that macromolecules exist. Since then, AUC has mainly found application in the field of biophysics, and this dominance still exists. Nevertheless, with the current advent of nanoscience and nanotechnology highlighted as the future technology of this century the focus turns backwards in history, and identifies AUC as one of the most powerful colloid solution analysis techniques with a solid and mature theoretical basis. This chapter will outline how the various AUC techniques can be applied to the classical analysis problems of colloid chemistry, and will highlight potentially useful but so far less applied techniques such as sedimentation equilibrium as well as sedimentation velocity applications, the most important AUC technique for colloid analysis. Developments in this field, starting with the pioneering work of Svedberg and covering more recent work as well will be outlined, but the focus will be more on the various possible AUC techniques for colloid analysis rather than an exhaustive overview of the tremendous amount of literature from the last 70 years. This...