To provide a method for producing a Group III nitride semiconductor light-emitting device, which allows the formation of a high-temperature AlN buffer layer on an uneven substrate. This production method comprises forming an Al layer or Al droplets on the uneven shape of the uneven substrate, forming an AlN buffer layer while nitriding the Al layer; and forming a Group III nitride semiconductor layer on the AlN buffer layer. In the forming an Al layer, the internal pressure of a furnace is 1 kPa to 19 kPa, the temperature of the uneven substrate is 900° C. to 1,500° C., and an organic metal gas containing Al is supplied at a flow rate of 1.5×10−4 mol/min or more.