Ga-doped zinc oxide (GZO) transparent conducting thin films were prepared by a polymer-assisted solution (PAS) process. The Ga concentration in the film was varied from 1 to 5 at.% by adjusting the mixing ratio of Zn- and Ga-source solutions formulated by coordinating Zn- and Ga-anionic complexes with a water-soluble polymer. The GZO-source solutions were spin-coated on glass substrates and heat-treated at elevated temperatures. The optimum Ga concentration was investigated by analyzing the electrical and optical properties of the PAS-coated films. The GZO film with 1 at.% Ga showed the lowest resistivity of 7.49 × 10⁻²Ω-cm and an optical transmittance of 85% at 550 nm with a film thickness of 107 nm. X-ray diffraction analysis revealed that the PAS-coated GZO films had the wurtzite crystal structure with a preferred orientation of (002). Higher post-annealing temperatures resulted in larger grain sizes and discontinuities were observed among the grains in the films. Multiple spin-coating steps were employed to increase the film thickness, resulting in the reduction in the sheet resistance of the PAS-coated GZO films from 7.0 kΩ∕sq. (single layer of GZO) to 0.7 kΩ∕sq. (four layers of GZO) without noticeable reduction in film transmittance.