We present a simple but accurate equation of state for double Yukawa fluids based on the variational series mean spherical approximation (VSMSA). This allows us to investigate the vapour–liquid equilibrium and its related thermodynamic properties. The comparisons with computer simulation results of the Lennard–Jones (LJ) potential suggest the importance of treating the attractive tail of the potential accurately via VSMSA. The estimated reduced critical parameters TC= 1.342, ρ C= 0.29 and PC= 0.135 are in good agreement with other ...