This study investigated the solubilization of valdecoxib in aqueous solutions of glycerol, propylene glycol, and poly(ethylene glycol) 400 at (298.15, 303.15, and 308.15) K. The analysis of valdecoxib was carried out by UV spectral measurements at lambda(max) of 204 nm. The solubility of valdecoxib increased with increasing mass fraction of glycerol, propylene glycol, and poly(ethylene glycol) 400 at (298.15, 303.15, and 308.15) K. For poly(ethylene glycol) 400 + water mixtures, the solubility of valdecoxib was higher when compared to the glycerol + water and propylene glycol + water mixtures. The solubilization power of glycerol, propylene glycol, and poly(ethylene glycol) 400 at (298.15, 303.15, and 308.15) K was 1.1, 1.5, and 1.8; 2.6, 2.8, and 2.9; and 3.0, 3.5, and 3.9, respectively.