A simple, fast and reproducible method for determination of chlorpromazine (CLP) is presented. Calibration curves are prepared for the 6.0 mol.dm−3solutions of 1.0×10−6to 1.0×10−4CLP which are oxidized with equivalent volumes of standard Ce+4solutions to a highly coloured (λmax=525nm.) semiquinone cation radical. Conventional photometric and photoacoustic techniques using carbon-black detection (CBD) gave consistent results and are used to calculate the CLP content of tablets and ampuls with a good precision, and an overall accuracy of 1.9% and ∼3% respectively.