Praziquantel is a medication used to treat schistosomiasis. It has low bioavailability due to poor solubility in water and common solvents, resulting in its availability only in a solid dosage form. This study is aimed to enhance the solubility of praziquantel by the use of various solubilizing agents. The solubility evaluation was conducted using the shake-flask method. The solvents were; buffered phosphate pH 7.4, 0.5% propylene glycol in buffered phosphate pH 7.4, 0.2% tween 80 in buffered phosphate pH 7.4, 30% methanol in buffered phosphate pH 7.4, and assessment of the solubility of the drug in 0.1 N hydrochloric acid, 0.2% sodium lauryl sulfate, and a mixture of 0.2% sodium lauryl sulfate in 0.1 N hydrochloric acid. The solubility of praziquantel was determined at a temperature of 37±2°C, and the concentrations were detected by high-performance liquid chromatography at λ=210 nm. The results show that the solubility of praziquantel was 124.3±2 µg/ml in 30.0% methanol in buffered phosphate pH 7.4, 100.6±2 µg/ml in 0.2% tween 80 in buffered phosphate pH 7.4, 112.4 µg/ml in 0.1 N hydrochloric acid, 370.29 µg/ml in 0.2% sodium lauryl sulfate, and 278.7 µg/ml in a mixture of 0.2% sodium lauryl sulfate in 0.1 N hydrochloric acid (pH 2). Thus, praziquantel can be considered a highly soluble drug in 0.2% sodium lauryl sulfate. Other surfactants may improve the solubility of such poorly soluble drugs.