This paper reports the vapor pressure and enthalpy of vaporization for benzene, toluene, p-xylene, and Tetralin between 1 and 16 bar measured by using an adiabatic flow calorimeter. The analysis of the results showed that the uncertainty of the data Is within ±0.0099 bar for vapor pressure and ±15 J/mol for enthalpy of vaporization, AW".