We present a model equation of state for C60 based on a variational series mean spherical approximation for a double Yukawa fluid. This allows us to investigate the liquid– vapour coexistence curve and calculate the thermodynamic properties of liquid C60. The comparisons with computer simulation results, based on the Girifalco potential, suggest the importance of treating the attractive tail of the potential accurately. The estimated critical parameters, Tc= 1943 K, ρc= 0. 477 nm− 3 and Pc= 34. 2 bar, are in good agreement with ...