The effect of inorganic salts (sodium chloride, sodium nitrate, sodium sulphate, zinc sulphate and ammonium sulphate) on the methyl isobutyl ketone-acetic acid-water system at 35 degrees C has been studied and the correct experimental procedure for the determination of the data of salt containing ternary liquid-liquid equilibrium (LLE) systems ascertained. The Campbell correlation is modified to fit the data of salt containing ternary liquid systems. The distribution data of these salt containing systems have been correlated through the use of the modified Nernst, modified Campbell and the Eisen-Joffe equations and the constants obtained have been used to predict extract phase solute concentrations and also to calculate the salt effect parameter. Results based on the modified Nernst equation show the following order of effectiveness of salts : ZnSO4 > Na2SO4 > (NH4)(2)SO4 > NaCl > NaNO3. The order of effectiveness of the salts based on the salt effect parameter derived from the modified Campbell and the Eisen-Joffe constants are also discussed.