According to one embodiment, there is provided a nonaqueous electrolyte battery including a positive electrode. The positive electrode includes a positive electrode active material-containing layer. The positive electrode active material-containing layer includes at least one lithium-nickel composite oxide and a conductive agent. The positive electrode active material-containing layer has, in a particle size distribution obtained by a laser diffraction scattering method, an average particle diameter d50 within a range of 1 μm to 5.5 μm, a maximum particle diameter within a range of 10 μm to 100 μm, a particle diameter d10 within a range of 0.5 μm to 3 μm, and X, represented by X=(d50−d10)/d50, within a range of 0.5 to less than 1.