In this paper, a methodology is developed for predicting the phase inversion point in dispersed liquid-liquid flows. It is suggested that phase inversion happens at the phase fraction where the difference in viscosities between the two possible dispersions, oil continuous and water continuous, is zero, which enables the transition from one continuous phase to the other. A large number of literature correlations were used to calculate the mixture viscosity and the predicted phase volume fractions for inversion were compared against experimental data. From the various viscosity models, those by Brinkman [Brinkman, H.C., 1952, The viscosity of concentrated suspensions and solutions, J Chem Phys, 20(4): 571], Roscoe [Roscoe, R., 1952, The viscosity of suspensions of rigid spheres, Br J Appl Phys, 3: 267-269], Furuse [Furuse, H., 1972, Viscosity of concentrated solution, Jpn J Appl Phys, 11(10): 1537-1541] and Pal [Pal, R., 2001, Single-parameter and two-parameter rheological equations of state for nondilute emulsions, Ind Eng Chem Res, 40: 5666-5674] always predicted phase inversion within the experimental range. In addition, the phase inversion points predicted with the proposed methodology were very close to both the experimental finding and model by Yeh [Yeh, G.C., Haynie Jr., F.H., Moses, R.A., 1964, Phase volume relationship at the point of phase inversion in liquid dispersions, AIChE J, 10(2): 260-265]. (C) 2008 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.