The aqueous solubility of a drug candidate is a vital physicochemical property that stops a drug candidate from proceeding further in the drug development processes. Classical solubility determination methods, which are commonly used in pharmaceutical laboratories, are expensive and time-consuming. In this work, an automated determination method is proposed that is based on a laser monitoring technique, and the validity of the measured solubilities is checked by comparing the measured solubilities of acetaminophen at various temperatures as proposed in various literatures. An additional set of acetaminophen solubilities in various concentrations of a surface active agent is measured at various temperatures, which has been reported for the first time, and it could be applied in the pharmaceutical industry, where solubilization of acetaminophen in aqueous solutions is required.