A partial least-squares calibration ( PLS) method has been developed for simultaneous quantitative determination of mepyramine maleate ( MAM), lidocaine hydrochloride ( LIH), and dexpanthenol ( DPA) in pharmaceutical preparations. The resolution of these mixtures has been accomplished by using partial least-squares ( PLS-2) regression analysis of electronic absorption spectral data without prior separation or derivatization. The experimental calibration matrix was constructed with 27 samples. The concentration ranges considered were 2, 3, 4 mu gmL(-1) for MAM, 2, 3, 4 mu gmL(-1) for LIH, and 8, 10, 12 mu gmL(-1) for DPA. The absorbances were recorded between 190 and 340 nm every 5 nm. The results show that PLS-2 is a simple, rapid, and accurate method applied to the determination of these compounds in pharmaceuticals.