The mutual solubilities for ternary systems of p-nitroacetophenone (1) + m-nitroacetophenone (2) + methanol (3), p-nitroacetophenone (1) + m-nitroacetophenone (2) + toluene (3), and p-nitroacetophenone (1) + m-nitroacetophenone (2) + ethyl acetate (3) were investigated through a steady method at 283.15, 298.15, and 313.15 K, respectively, under a local ambient pressure of 101.2 kPa. The isothermal phase diagrams of the three systems were constructed in terms of the obtained mutual solubilities. At a fixed temperature, there were two neat solids formed, namely neat p-nitroacetophenone and neat m-nitroacetophenone, which were recognized through Schreinemakers' wet residue method. The crystallization regions of neat p-nitroacetophenone and neat m-nitroacetophenone increased with decreasing temperature. The mutual solubility was correlated through the Wilson and NRTL equations. The relative average deviations for p-nitroacetophenone + m-nitroacetophenone + methanol/toluene/ ethyl acetate systems were, respectively, 4.44 X 10(-2), 3.86 X 10(-2), and 3.35 X 10(-2) for the NRTL equation and 4.33 X 10(-2), 2.51 X 10(-2), and 2.29 X 10(-2) for the Wilson equation. The acquired solubility data and the ternary phase diagrams for the three systems were very significant for designing and optimizing the purification process of p-nitroacetophenone and m-nitroacetophenone mixtures.