In this paper, the influence of hydrogen and argon plasma treatment on the electro-optical and structural properties of aluminum-doped zinc oxide (AZO) and indium tin oxide (ITO) films were studied. The films were exposed for different times and at various plasma powers. AZO films did not reduce for all plasma conditions, while ITO films were deteriorated when exposed to hydrogen plasma for even a short treatment time. The argon plasma has little effect on the properties of AZO and ITO films. When the ITO films were exposed to Ar plasma for a long time, however, the optical properties of ITO films were strongly influenced.