A rapid capillary zone electrophoresis method has been developed capable of quantifying 0.05% of R-enantiomer and assaying the main component in escitalopram formulations. Many parameters influencing enantioseparation were investigated, which include chiral selectors, buffer composition and pH, applied voltage, capillary length, temperature, and rinsing procedure. Optimal separation conditions were obtained by using a 25 mM phosphate buffer at pH 7.0, containing 1.6% (w/v) sulfated-eta-cyclodextrin with short-end injection at 0.5 psi for 5 s. Online UV detection was performed at 205 nm. A voltage of -20kV was applied and the capillary temperature was kept at 25 degrees C. Separation was achieved in less than 2 min. The method was further validated, including robustness, stability of the solution, selectivity, linearity (escitalopram from 0.25 mu g/mL to 600 mu g/mL, y = 1528.3 x +1812.9; R2 = 0.9999), LOD and LOQ (0.08 and 0.25 mu g/mL, respectively), precision and accuracy. The proposed method was then applied to the quality control of the bulk sample and tablets of escitalopram (10 mg).