One of the most challenging areas to which molecular simulation has contributed significantly over the last decades is without a doubt the accurate and efficient prediction of fluid phase equilibria. In this work we combine two of the most powerful methods that have greatly enhanced our ability to simulate accurately fluid phase equilibria: (a) the “Gibbs ensemble” method (A.Z. Panagiotopoulos, Molecular Physics 61 (1987) 813–826) and (b) the multiple histogram method (A.M. Ferrenberg, R.H. Swendsen, Physical Review Letters 61 (1988) 2635–2638). The result of such combination is a simple and very accurate method of predicting fluid phase equilibrium close to and away from the critical point.