A high-performance liquid chromatographic method for the determination of demecarium bromide and related process intermediate and companion products is described. The compounds of interest are separated by isocratic reversed-phase chromatography on a mu Bondapak CN column using UV detection. The reproducibility of the method and stability of demecarium bromide is demonstrated. Applications presented for the method include quantitation of demecarium bromide in aqueous solutions and control of the raw material.