A capillary zone electrophoresis (CZE) method was developed for the quantitative analysis of fosinopril sodium. Validation parameters of the CZE method were evaluated and compared to an existing LC method. In terms of precision and sensitivity. LC performance was superior to that of the CZE method for this application. The CZE method achieved better selectivity for several degradants of interest within a much shorter analysis time than did the LC method. Effects of detection wavelength, applied voltage and buffer concentration on optimization of the CZE method are presented. Effects of diluent composition on capillary loading and peak behaviour are also discussed.