Patterned polymer thin films were prepared by spin-coating a solution consisting of an acryl monomer of 2-(9H-carbazol-9-yl)ethylmethacrylate, a photoinitiator of 4-(dimethylamino)benzophenone, and a phosphorescent dopant of iridium(III) bis(2-phenylpyridinate(4-vinylphenylpyridine)). The film was exposed to UV light through a photomask and rinsed with an organic solvent to develop a patterned polymer thin film. A mixture of tetrahydrofuran and 1,4-dioxane was used as the spin-coating solvent, and ethanol was used as the developing solution. The effects of solvent, exposure time, UV intensity, and the phosphorescent dopant were examined to optimize the patterning condition. The patterned film was utilized as an emissive layer to construct an organic light-emitting diode.