The evaluation of some of the principal correlations that describe adsorption equilibria for gases at supercritical temperatures is carried out. Based on the experimental data for the adsorption of methane and nitrogen on a carbon molecular sieve 5A (Takeda) it is found that the four-parameter characteristic curve of Amankwah and Schwarz [1] seems to be superior to the three-parameter Dubinin-Astakhov equation [2]. It is also demonstrated that, since the parameters visibly depend upon both the type of equation and the accuracy of the experimental data and regression procedures employed, caution should be exercised in ascribing any specific physical significance to the values of these parameters.