This review article with 244 references describes recent developments in capillary electrophoresis of proteins and covers the two years since the previous review (Dolnik, V. Hutterer, K. Electrophoresis 2001, 22, 4163-4178) through Spring 2003. It covers topics related to CE of proteins including modeling of the electrophoretic properties of proteins, sample pretreatment, wall coatings, improving selectivity, detection, special electrophoretic techniques, and applications.