This review, as a continuation of two earlier reports, gives an overview of the recent developments, over the period from 2005 until now, in the use of electrophoretically mediated microanalysis (EMMA) methodology for the on-line study of enzymatic reaction and derivatization. The article is divided into two parts: (i) on-line enzymatic reaction by EMMA and (ii) on-line derivatization by EMMA. Following a brief introduction, a literature overview on enzymatic reaction is provided. The second part starts with an introduction of the purpose of derivatization and the nomenclature used in the area of in-capillary derivatization based on EMMA. The development of more integrated analytical platform that combines in-capillary derivatization and sample preconcentration is discussed. Reported derivatization procedures are summarized.