Determination of amino acids (AA) in biological fluids plays an important role in clinical research. Attention has been focused on separation methods offering a high separation efficiency, small volume of injected sample and short time of analysis. Capillary electrophoresis (CE) is one of the analytical methods that meets all these demands and, in addition, allows to overcome some technical obstacles in analysis of biological materials. This article provides a review of recent progress in the CE analysis of proteinogenic AAs in biological fluids. Principles and applications of various CE detection techniques are discussed, including those based on direct UV photometry, fluorimetry, indirect photometry, electrochemistry and conductivity. It is shown that the contactless conductivity detection (CCD) is superior to other detection techniques in the CE analysis of the whole profile of proteinogenic AAs occurring in their native forms in biological fluids. Apart from a high sensitivity, the CE/CCD method makes it possible to avoid complicated pretreatment of biological samples.