The Romanian peat was used as low-cost adsorbent to remove Cd(II) ions from aqueous solutions. The cadmium adsorption capacity of the peat was studied as a function of the solution pH (3-5.5) and temperature (293 – 333 K). Adsorption capacity was found to increase with the pH increasing and temperature decreasing and attained a maximum value of 27.9 mg/g at pH = 5±0.1 (acetate buffer) and 293 K. In addition, various thermodynamic parameters such as free energy change (ΔG0), enthalpy change (ΔH0), entropy change (ΔS0) along with isosteric heat of sorption (ΔHx) were calculated. The adsorption of Cd (II) ions by peat was found to be a spontaneous and exothermic process, which is governed by electrostatic interactions (physisorption). FT-IR analysis of the peat before and after Cd (II) sorption suggests electrostatic attraction between cadmium cations and negatively charged –COO- groups present on the peat surface.