The key factor for designing of micro- and nanosized particles production processes is determination of a solid solute solubility. In the current investigation, for the first time, the solubility of sodium valproate in supercritical CO2 was investigated. Solubility investigations were conducted at different temperatures (308.15-338.15 K) and pressure values (12-27 MPa). Sodium valproate provided mole fraction solubility values of 0.05 X 10(-5) to 3.71 X 10(-5) within the experimental range studied. For the studied system, data correlation has been examined by equations of state (EoSs) including Soave-Redlich-Kwong (SRK), Peng-Robinson (PR), and Estevez models as well as SAFT-VR and four semi-empirical models (Kumar and Johnston, Mendez-Santiago and Teja, Jouyban et al., Sodeifian et al., Bartle et al., Chrastil's models and Reddy and Garlapati models). Statistical criteria (AARD, R-adj, and F-value) were used to appraise their precision. The analysis of variance (ANOVA) also indicated the superior performance of the PR, SRK, Estevez, and SAFT-VR EoSs. Furthermore, density-based models generally exhibited excellent agreement with the experimental data.