We performed a comprehensive theoretical and experimental study on concurrent silanization and co-condensation of tetraethyl orthosilicate (TEOS) and 2-Methoxy(polyethyleneoxypropyl)trimethoxysilane (PEOS) under basic hydro-organic medium for straightforward production of a covalent neutral coating for capillary electrophoresis. It is proposed that the steric hindrance induced by the large structure of PEOS renders it difficult to obtain a facile direct reaction with the silanols on the capillary’s internal surface. Rather, the addition of TEOS for silanization and cross-linkage is efficient to retain PEOS anchored on the silanol surface, thus producing a neutral layer. Performance of the produced neutral capillary in terms of suppression and stability of the electroosmotic flow, as well as application of this new neutral coating for the separation of low molecular weight carboxylic anions and proteins of both positive and negative charges were evaluated.