Abstract: Chlorpromazine phosphoresces strongly in acidic and basic media. In HCl-ethanol solution, it gives a strong phosphorescence with maximum excitation at 258 and 314 nm and maximum emission at 494 nm. After oxidation with H₂O₂, a new maximum emission at 460 nm appeared whereas the 494 nm peak disappeared. The life-time of phosphorescence was shown to be 0.31 s, but it became shorter after oxidation.Chlorpromazine may be extracted by chloroform from blood either in acidic or basic medium. A simple method for the determination of chlorpromazine in blood was developed with 100% recovery.