Electrical properties of ac plasma polymerized aniline thin films are investigated with a view of determining the dominant conduction mechanism. The current-voltage (I-V) characteristics in symmetric and asymmetric electrode configuration for polyaniline thin films in the thickness range from 1300 to 2000 Angstrom are investigated. From the studies on asymmetric electrode configuration, it is found that the dominant conduction mechanism in these films is of Schottky type. (C) 2002 Elsevier Science B.V. All rights reserved.