Provided is a method of patterning an organic thin film which can prevent surface damage of an organic semiconductor layer. Also, an organic thin film transistor that can reduce an off-current and can prevent surface damage of the organic semiconductor layer and a method of manufacturing the organic thin film transistor, and an organic electroluminescence display device having the organic thin film transistor are provided. The method of patterning the organic thin film includes forming the organic thin film on a substrate, selectively printing a mask material on a portion of the organic thin film, dry etching an exposed portion of the organic thin film using the mask material, and removing the mask material.