The partial molar volumes and compressibilities of an anti-inflammatory drug sodium salicylate in aqueous-CTAB solutions have been determined from volumetric and ultrasonic data using standard methods. The refractive indices of these ternary solutions were measured and atomic polarizations were calculated at 30°C. The specific acoustic impedance (Z) and relative association (RA) of studied solutions are also calculated. Partial molar volumes and compressibilities have been explained in terms of drug-solvent and drug-surfactant interactions. CTAB showed significant effect on the partial molar volumes and compressibilities of aqueous solutions of sodium salicylate.