In the present paper, a study of temperature behaviour of the liquid-liquid equilibrium in ternary systems N,N-dimethylformamide + 2-methylpentane + methanol and N,N-dimethylformamide + methylcyclohexane + methanol. The analysis of critical curves of the liquid-liquid equilibrium by means of the regular solution model was carried out. The acquired predictions were subsequently verified experimentally. (c) 2005 Elsevier B.V. All rights reserved.