There is provided a nanostructure semiconductor light emitting device including a base layer formed of a first conductivity-type nitride semiconductor and a plurality of light emitting nanostructures disposed to be spaced apart from one another on the base layer. Each of the plurality of light emitting nanostructures includes a nanocore formed of the first conductivity-type nitride semiconductor, a stress control layer disposed on a surface of the nanocore and including a nitride semiconductor containing indium, an active layer disposed on the stress control layer and including a nitride semiconductor containing indium, and a second conductivity-type nitride semiconductor layer disposed on the active layer.