The solubility of 1,1'-(butane-1,4-diyl)-bis(3-methyl-1H-imidazolium-1-yl) dihexafluorophosphate in water, acetophenone, cyclohexanone, acetylacetone, and 2-butanone was measured at temperatures from (283.15 to 333.15) K by a laser monitoring observation technique at atmospheric pressure. The experimental data were correlated with the modified Apelblat equation, which can be used as a useful model in the purification process of 1,1'-(butane-1,4-diyl)-bis(3-methyl-1H-imidazolium-1-yl) dihexafluorophosphate.