A nitride semiconductor light-emitting device is formed of an n-type nitride semiconductor layer, a trigger layer, a V-pit expanding layer, a light-emitting layer, and a p-type nitride semiconductor layer provided in this order. The light-emitting layer has a V-pit formed therein. The trigger layer is made of a nitride semiconductor material having a lattice constant different from that of a material that forms an upper surface of the n-type nitride semiconductor layer. The V-pit expanding layer is made of a nitride semiconductor material having a lattice constant substantially identical to that of the material that forms the upper surface of the n-type nitride semiconductor layer, and the V-pit expanding layer has a thickness of 5 nm or more and 5000 nm or less.