A method for producing a Group III nitride semiconductor light-emitting device includes an n-type layer, a light-emitting layer, and a p-type layer, each of the layers being formed of Group III nitride semiconductor, being sequentially deposited via a buffer layer on a textured sapphire substrate. A buried layer is formed of Group III nitride semiconductor on the buffer layer, at a temperature lower by 20° C. to 80° C. than the temperature of 1000° C. to 1200° C. when the n-type layer is deposited on the buried layer. The texture provided on the sapphire substrate may have a depth of 1 μm to 2 μm and a side surface inclined by 40° to 80°. A preventing layer may be formed of GaN at 600° C. to 1050° C. so as to cover the entire top surface of the buffer layer.