Reduction of graphene oxide (GO) can be used to improve the physical and electronic characteristics of rGO through de-oxygenation and restoration of π-conjugation. Here, the gradual and controllable thermal reduction of GO film formed by drop-casting method was carried out at low temperatures (100 − 350 °C) in ambient conditions with simultaneous electrical measurements. The conductivity of GO film depended on the level of reduction. Electrical measurements show a decrease and then an increase in electrical current after > 150 °C with a maximum change of five orders in current at 300 °C in comparison to GO. The role of functional groups on the evolution of electrical conductance during reduction has been investigated by correlating the FTIR spectroscopy and electrical conductivity. It is shown that the changes in conductivity is governed by two processes, first process is mainly associated with water and OH groups desorption and second process is mainly associated with restored graphene sp² network. The process, therefore, lends itself to the production of conductive reduced GO suitable for many applications including flexible electronics, TCO layer in solar cells, gas and temperature sensors.