A nitride semiconductor laser element includes a lower clad layer, a lower adjacent layer, a quantum well active layer, an upper adjacent layer and an upper clad layer in this order. The quantum well active layer includes a plurality of well layers formed of undoped InGaN, and an undoped barrier layer sandwiched between the well layers. The barrier layer includes a first layer formed of InGaN, a second layer formed of GaN, and a third layer formed of InGaN. The In composition ratio of the first layer and the In composition ratio of the third layer are less than half the In composition ratio of the well layer.