Hydrogen adsorption was studied on treated multi-walled carbon nanotubes (MWCNTs). The amounts of hydrogen adsorbed on this adsorbent were measured at three temperatures (298, 273 and 263 K) and various pressures from 10 up to 70 bar in a volumetric adsorption apparatus. In the studied ranges of operational conditions, the maximum adsorbed hydrogen was determined as 0.28 wt%, at the lowest temperature of 263 K and the highest pressure of 70 bar, by the static measurements at the equilibrium condition. The experimental adsorption isotherms were obtained at different temperatures and they were correlated by Dubinin-Astokhov (DA), Sips, Freundlich and Dubinin-Rudushkevich (DR) equations. The isosteric heat of adsorption was determined from both experimental isosters and isotherm models as a function of the adsorbed amount. The isosteric heats of adsorption revealed that MWCNTs would be an energetically heterogeneous surface. Sips model showed a better fitting of the experimental and theoretical isosteric heats of adsorption values and indicated a weak temperature dependency of the isosteric heat.