In capillary electrophoresis, electrokinetic separations are carried out in tiny capillaries at high voltages, thus obtaining high efficiencies and excellent mass sensitivities. Main features of capillary electrophoresis are versatility of application (from inorganic ions to large DNA fragments), use of different separation modes with varying selectivity, extremely low demands on sample volume, negligible operating costs, possibility of interfacing with different detection systems, ruggedness, and simplicity of instrumentation. Capillary electrophoresis applications in forensic sciences have appeared only recently but are now growing rapidly, particularly in forensic toxicology. Basic principles of capillary electrophoresis are described from both instrumental and analytical points of view, and its primary applications in analyzing illicit or controlled drugs are presented and discussed. The authors conclude that the particular separation mechanism and the high complementarity of capillary electrophoresis make it a powerful tool in forensic toxicology investigations. 43 references and 4 figures