The solubilities of dioxopromethazine hydrochloride (DPZ) in water, acetic acid, ethanol, methanol, N,N-dimethylformamide, N-methyl ketopyrrolidide, and acetone between (278 and 328) K were measured using a laser monitoring observation technique. Results of these measurements were correlated with a semiempirical equation. For seven solvents studied, the data are well fitted with a semiempirical equation.