In this study, a highly stable and flexible silver nanowires (AgNWs)/reduced graphene oxide (RGO) composite transparent conductive film (TCF) was obtained by coating a solution of AgNWs and graphene oxide (GO) on polyethylene terephthalate (PET) with citrate reduction of GO. The AgNWs were synthesized by the microwave-heating polyol method, whereas GO was prepared by Hummer’s method. The synthesis parameters of interest include microwave power and reaction time. The surface morphologies of the AgNWs and GO were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), whereas the synthesized nanocomposite was characterized by X-ray diffractometry (XRD), Raman spectroscopy, and Fourier-transform infrared (FT-IR) spectroscopy. The experimental results showed that the suitable conditions of microwave heating for AgNW synthesis were 600 W and 40 min. The measurement of optoelectronic properties showed that the light transmittance of AgNWs was 80.13%, which is slightly higher than the requirement of TCFs of 80%. The sheet resistances of AgNWs without and with 3 wt.% RGO were 205.26 and 180.22 Ω/sq, respectively. Furthermore, the film stability was investigated in the ambient air, moist, and acetone environments. The increase in the AgNW sheet resistance after five weeks in the atmosphere was 123.2%, whereas with RGO protection, the increases in the sheet resistance were as low as 16.5, 27.3, and 48.1% in the ambient air, moist, and acetone environments, respectively. On the other hand, no significant variation of sheet resistance was detected even after the film was subjected to bend loading. It was thus shown that RGO can be used as a protective layer of AgNWs and that flexible AgNWs/RGO TCFs have the potential to be widely used in the optoelectronic industry.