A nickel-metal hydride secondary battery comprising electrode group comprising positive electrode comprised mainly of nickel hydroxide, negative electrode comprised mainly of a hydrogen storage alloy, and separator being disposed between the positive electrode and the negative electrode, wherein the electrode group is sealed in battery casing, together with an alkali electrolyte liquid, wherein, in the battery, a W element and an Na element are present simultaneously. The nickel-metal hydride secondary battery of the present invention is advantageous not only in that it exhibits high utilization of the active material and excellent self-discharge characteristics in a high temperature storage as well as high charging efficiency in a high temperature environment, but also in that it has excellent large current discharge characteristics.