Experimental Solubilities of chlordiazepoxide, diazepam, and lorazepam in polyethylene glycol 200 (PEG 200) + water mixtures at 303.2 K were reported. The Solubility of each drug increased exponentially with the addition of PEG 200 and reached file maximum Value in neat PEG 200. The Jouyban-Acree model was used to mathematically describe the experimental data, and the Solubilities were predicted using a previously trained version of the Jouyban-Acree model for PEG + water Mixtures and the Solubility data in monosolvents. The overall mean relative deviations of the models were 3.7 % and 18.3 %, respectively, for the fitted model and the trained version.