Abstract The saturated vapor pressure of 2-phenyloxirane (PhOxi) was determined using a rose type equilibrium cell at different temperatures ranging from 303.15 K to 465.65 K. The experimental data were fitted with the Antoine and Clarke−Glew equations by minimizing the error of the maximum likelihood objective function using Britt – Luecke algorithm, which yielded Antoine parameters (A = 6.3964, B = 1999.56, C = −11.91 K) and standard molar vaporization enthalpy ( Δ l g H m 0 (298.15 K) = 40.97 kJ.mol−1). The molar enthalpy and entropy of vaporization at boiling point was found out to be 40.36 kJ.mol−1 and 86.48 J.mol−1.K−1, respectively. The critical state parameters of PhOxi, such as critical temperature (Tc), pressure (pc), and volume (Vc), were estimated by the group contribution method (GCM) introduced by both Joback and Reid (JR) model and Nannoolal (NA) model. The acentric factor (ω) of PhOxi was estimated from these critical parameters and the reduced saturated vapor pressures calculated from both the Clarke−Glew equation and the Antoine equation.