According to one embodiment, a semiconductor light emitting device includes an n-type semiconductor layer, a p-type semiconductor layer, and a light emitting portion. The light emitting portion is provided between the semiconductor layers and includes barrier layers and well layers alternately stacked. An n-side end well layer which is closest to the n-type semiconductor layer contains InwnGa1-wnN and has a layer thickness twn. An n-side end barrier layer which is closest to the n-type semiconductor layer contains InbnGa1-bnN and has a layer thickness tbn. A p-side end well layer which is closest to the p-type semiconductor layer contains InwpGa1-wpN and has a layer thickness twp. A p-side end barrier layer which is closest to the p-type semiconductor contains InbpGa1-bpN and has a layer thickness tbp. A value of (wp×twp+bp×tbp)/(twp+tbp) is higher than (wn×twn+bn×tbn)/(twn+tbn) and is not higher than 5 times (wn×twn+bn×tbn)/(twn+tbn).