Nanocomposite of polyaniline (PANI) with natural clinoptilolite (Clino) was prepared. Formation of nanocomposite and incorporation of polyaniline in the clinoptilolite channels was confirmed and characterized using FTIR spectroscopy studies. X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM) and cyclic voltammetry techniques. The anticorrosive properties of a 20 mu m thickness coating of PANI/Clino nanocomposite with various weight ratios (1, 3 and 5%, w/w) of clinoptilolite content on iron Coupons was evaluated and compared with pure polyaniline coating. According to the results in acidic environments PANI/Clino nanocomposite has enhanced corrosion Protection effect in comparison to pure polyaniline coating. Comparative experiments revealed that PANI/Clino nanocomposite with 3% (w/w) clinoptilolite content has the best protective properties. Further experiments showed that the PANI/Clino nanocomposite has considerably different corrosion protection efficiencies in various corrosive environments. (C) 2009 Elsevier B.V. All rights reserved.