This study addresses the removal of a heavy metal, Cr (VI), from aqueous solutions by using dried Psedeuvernia furforcea biomass as biosorbent. The effects of factors, such as the initial chromium concentration, contact time, temperature, biosorbent dosage and mixing rate on biosorption of the heavy metal was investigated. Furthermore, the fitting of adsorption data on Langmuir, Freundlich, BET, Temkin, Redlich-Peterson, Henderson, Smith, Halsey and Harkins-Jura adsorption isotherm models was investigated. In order to explain the metal-functional group binding mechanisms, FTIR analysis was carried out. The sorption equilibrium time was determined to be 8 hours. The amount of Cr (VI) adsorbed onto Psedeuvernia fulforcea increased with increasing sorbent dosage and increasing temperature indicating endothermic nature of biosorption process: The results suggest that the physical interactions between sorbent particles and sorbate ions play an important role for the adsorption of Cr (VI) onto the biosorbent. It was found that the biosorption data of Cr (VI) by Psedeuvernia furforcea biomass were fit on the Freundlich adsorption isotherms at 293, 313, and 333K. From the experimental results, it can be concluded that Psedeuvernia furforcea can be used as an economical sorbent in the removal of these heavy metal ions.