CdS thin films were deposited by thermal evaporation method onto glass substrates without any doping. As a result of the structural and electrical investigation it was found that CdS thin films were of the polycrystalline structure and n-type / and of the transmission analysis optical band gap was found to be around 2.4 eV. Temperature dependent conductivity measurements were carried out in the range of 180 K &ndash / 400 K. The dominant conduction mechanism is identified as tunnelling between 180 K &ndash / 230 K and thermionic emission between 270 K and 400 K. To produce Schottky devices, CdS thin films were deposited onto the tin-oxide and indium-tin-oxide coated glasses, by the same method. Gold, platinum, carbon and gold paste were used as metal front contact in these devices. The area of these contacts were about...... Temperature dependent current-voltage measurements between 200 K and 350 K, room temperature current-voltage measurements, capacitance-voltage measurement in the frequency range 1 kHz &ndash / 1 MHz and photoresponse measurements were carried out for the characterization of these diodes. Ideality factor of the produced Schottky devices were found to be at least 1.5, at room temperature. Dominant current transport mechanism in the diodes with gold contacts was determined to be tunnelling from the temperature dependent current voltage analysis. Donor concentration was calculated to be about ........ from the voltage dependent capacitance measurement.