A nitride semiconductor laser device comprises, on a principle face of a nitride semiconductor substrate: a nitride semiconductor layer having a first conductivity type; an active layer comprising indium, and a nitride semiconductor layer having a second conductivity type that is different from said first conductivity type, and on the surface of which is formed a stripe ridge; said principal face of said nitride semiconductor substrate having an off angle a (.theta..sub.a) with respect to a reference crystal plane, in at least a direction substantially parallel to said stripe ridge.