A hand-held level and plumb tool that includes a homogeneous, L-shaped body, a first level indicating device, and a second level indicating device. The L-shaped body has first and second legs arranged at a 90° angle. The first leg defines an interior side, an exterior side, a central panel extending between the sides, and a length in extension of the first leg from the second leg to a free end. A slot is formed through a thickness of the central panel and extends along at least a majority of the length. The first level indicating device is assembled to the central panel of the first leg at a location spaced from the slot. The second level indicating device is assembled to the second leg. One or both of the legs can include measurement-related indicia selected in accordance with staircase construction standard dimensions.