Vapor-liquid equilibrium measurements have been carried out for the propane-ethanol system at 325°, 350°, 375°, 400°, and 425°K. The pressures corresponding to these temperatures ranged from 569.5 kPa (82.6 lb/in.2abs) to 5 618.5 kPa (814.9 lb/in.2abs). Altogether, nineteen experimental determinations were made; one of these determinations at 425°K approached the critical state, and this measurement assisted in establishing the entire critical temperature and critical pressure profiles for this binary system. The information associated with these measurements enabled the construction of isothermal bubble point-dew point relationships up to 500°K. These results made possible the establishment of isothermal relationships of K values vs. pressure for the components of the propane-ethanol system. Calculated K values for this system using the BWR method and the SRK method were found to be in fair agreement with corresponding experimental values.