The liquid-liquid phase equilibria of substituted perfluoro-n-octane (1 Br-perfluoro-n-octane, 1H-perfluoro-n-octane, 1H,8H-perfluoro-n-octane) + n-octane were experimentally determined by turbidimetry in the temperature range between 270 K and 330 K and at the vapor pressure of the mixture. The measured equilibrium data were correlated with an equation derived from renormalization group (RG) theory and with soft-SAFT Equation of State. The LLE data of the binary mixtures of n-octane + substituted perfluoro-n-octane were compared with n-octane + perfluoro-n-octane data. The results indicate an increasing solubility with 1 Br-perfluoro-n-octane and show that the introduction of second hydrogen atom has almost no effect on phase equilibrium. (C) 2008 Elsevier B.V. All rights reserved.