Sorption and diffusion of n-pentane in pellets of 5A zeolite (Rhone-Poulenc) have been studied by gravimetric and ZLC techniques between 373 and 573 K and at partial pressures up to 0.6 bar. Adsorption isotherms were satisfactorily described by a localized adsorption model developed by Nitta et al. (1984) with only one temperature-dependent parameter (coefficient of Henry’s law). The isosteric heat of adsorption is around 12.5 kcal/mol. Kinetic data clearly show that macropore diffusion is the controlling mass-transfer mechanism. Between 473 and 573 K, pore diffusivities range from 0.10 to 0.14 cm(2)/s in the system He-n-C-5 and from 0.07 to 0.09 cm(2)/s in the system N-2-n-C-5.