Electrical resistivity of polycrystalline pyrite thin films has been investigated at 300 Kless than or equal toTless than or equal to615 K. Curved Arrhenius type plots are interpreted as due to a high density of acceptor states created by interacting Fe vacancies partially compensated by S vacancies. Mean energy value of the narrow band created by those Fe vacancies has been measured as similar to 0.11 eV and its standard deviation as similar to0.05 eV. Implications of this view on other properties of the films are discussed. (C) 2003 Elsevier B.V. All rights reserved.