An isocratic chiral stationary phase high-performance liquid chromatographic (CSP-HPLC) method has been developed and validated for the quantitation of (S)-isomer in Alogliptin Benzoate. Separation was achieved with a Lux cellulose 2 (250×4.6mm, 5μm) column. The ratio of ethanol and diethyl amine in the mobile phase were optimized to obtain the best separation. UV detection was performed at 230 nm. The described method is linear over a range of LOQ – 1.5 μg/mL of (S)-isomer. The mean recovery of (S)-isomer was found to be in the range of 100–102%. The method is simple, rapid, accurate, selective and precise, useful in the quality control of bulk manufacturing.