The present invention provides a Group III nitride semiconductor light-emitting device exhibiting improved light extraction performance. In the production method, a p cladding layer of p-AlGaN is formed by the MOCVD method on a light-emitting layer at a pressure of 30 kPa and with an Mg concentration of 1.5×1020/cm3. A plurality of regions with a nitrogen polarity is formed in the crystals with a Group III element polarity, and thus the p cladding layer has a hexagonal columnar concave and convex configuration on the surface thereof. Subsequently, a p contact layer of GaN is formed by the MOCVD method, in a film along the concave and convex configuration on the p cladding layer.