This article describes the most important articles that have been published on amino acid analysis using CE during the period from June 2007 to May 2009. It follows the format of the previous articles of Smith [Electrophoresis 1999, 20, 3078-3083], Prata et al. [Electrophoresis 2001, 22, 4129-4138] and Poinsot et al. [Electrophoresis 2003, 24, 4047-4062; Electrophoresis 2006, 27, 176-194; Electrophoresis 2008, 29, 207-223]. For several years we have presented the new developments in amino acid analysis with CE which describe the use of laser emitting diodes for LIF as well as via MS. In addition, we describe articles concerning clinical studies and neuroclinical applications.