The solubility of diosgenin in four pure imidazolium-based ionic liquids, including [C(4)mim]NO3 (1-butyl-3-methylimidazolium nitrate), [C(2)mim]NTf2 (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide), [C(4)mim]NTf2 (1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide), and [C(8)mim]NTf2 (1-octyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide), were determined in the temperature range from (312.85 to 363.95) K at atmospheric pressure via a laser monitoring observation method. The solubility of diosgenin in the selected ionic liquids increased with increasing temperature. Diosgenin was especially soluble in [C(8)mim]NTf2, with a mole fraction of (0.287-1.630) x 10(-3) at (312.85 to 332.25) K. The experimental data were successfully correlated using the dual-parameter empirical equation, Apelblat equation, and lambda h equation.