Disclosed is a method for fabricating a lateral double diffused metal oxide semiconductor (LDMOS) transistor, which includes implanting impurity ions onto a semiconductor substrate to form a drift region and a body region, forming a photoresist pattern to expose a region where an insulating oxide film is to be formed on the semiconductor substrate, implanting first impurity ions through the photoresist pattern to form a first impurity region, where the insulating oxide film is to be formed, in the semiconductor substrate, forming an insulating oxide film and an outer insulating oxide film on the semiconductor substrate by an oxidation process, and forming a gate electrode on the semiconductor substrate.