An organic thin film transistor (OTFT) having an adhesive layer and a method of fabricating the same. The OTFT includes a gate electrode formed on a substrate, a gate insulating layer formed on the gate electrode and on remaining exposed portions of the substrate, an adhesive layer formed on the gate insulating layer, source/drain electrodes formed on the adhesive layer, and a semiconductor layer formed on the source/drain electrodes and on the adhesive layer. The gate insulating layer and the semiconductor layer are organic, the adhesive layer providing adhesion between the source/drain electrodes and the gate insulating film while preventing gate leakage current while also improving contact resistance.