An object is to provide a method of manufacturing a nitride semiconductor light emitting device having high light emission output and allowing decrease in forward voltage (Vf). The invention is directed to a method of manufacturing a nitride semiconductor light emitting device including at least an n-type nitride semiconductor, a p-type nitride semiconductor and an active layer formed between the n-type nitride semiconductor and the p-type nitride semiconductor, wherein the n-type nitride semiconductor includes at least an n-type contact layer and an n-side GaN layer, the n-side GaN layer consists of a single or a plurality of undoped and/or n-type layers, and the method includes the step of forming the n-side GaN layer by organic metal vapor deposition with the growth temperature set within the range of 500 to 1000° C., such that the n-side GaN layer is formed between the n-type contact layer and the active layer.