The electrical properties, including current-voltage (I-V) and capacitance-voltage (C-V) characteristics, of ITO/polyaniline/Al and ITO/polyaniline/Zn Schottky diodes have been investigated. Polyaniline (PANI) was prepared chemically and doped with 2-acrylamido-2-methyl-1-propanesulfonic acid sodium salt (AMPSNa). The maximum conductivity value for PANI-AMPSNa films was 1.8 × 10−2 S/cm at 0.5 weight ratio of AMPSNa. The values of various junction parameters such as ideality factor, barrier height and charge carrier concentration were calculated based on the thermionic emission theory. Zn electrode showed better rectifying behavior with PANI-AMPSNa film than Al electrode. The obtained C-V characteristics showed that the charge carrier concentration is in the range of 1016/cm3.