Electrochemical impedance spectroscopy was used to measure the charge transfer resistance of the reaction: Fe³⁺ + e^- = Fe²⁺ and electrical double layer capacitance on pyrite electrodes of different origin both freshly polished and conditioned in the solutions of several surface active substances which may be used as potential inhibitors of the oxidation of pyrite. The following substances were used for conditioning of the pyrite samples: sodium dodecylsulfate (SDS), sodium oleate (NaOL), n-octanol (n-OA), dodecyltrimethylammonium chloride (CTACl), 2-mercaptobenzthiazole (MBT) and bis(2-etylhexyl) phosphate (D2EHP). The highest degree of adsorption, and the highest increase in the charge transfer resistance was observed for MBT, NaOL and D2EHP. Those compounds can be used as inhibitors of the pyrite oxidation.