Isothermal vapor-liquid equilibria were measured for 2-propanol + octane and 2-propanol + 2,2,4-trimethylpentane at 348.15 K, The measurements were made in a Rogalski-Malanowski-type still with circulation of both vapor and liquid phases, Both binary isothermal systems form a maximum pressure azeotrope. The azeotropic data are x(1)(AZ) = 0.882 mole fraction and P(AZ) = 78.20 kPa for 2-propanol (1) + octane (2) and x(1)(AZ) = 0.637 mole fraction and P(AZ) = 96.24 kPa for 2-propanol (1) + 2,2,4-trimethylpentane (2). The experimental data were checked for thermodynamic consistency by using three conventional tests, The activity coefficients of both systems were best correlated with the non-random two-liquid (NRTL) equation.