The present invention provides a method for inspecting a crankshaft, which enables accurate detection of defects which occur partially in the crankshaft, such as underfills and dent flaws, by discriminating these defects from bending and torsion over an entire length of the crankshaft. The present invention includes steps of: acquiring three-dimensional point cloud data over an entire length of a measurement object region of a crankshaft S by an optical three-dimensional shape measurement device 1; dividing the acquired three-dimensional point cloud data to create a plurality of subregion three-dimensional point cloud data, each of the subregion three-dimensional point cloud data respectively corresponding to each of a plurality of subregions of the crankshaft along a direction parallel to the rotational center axis L of the crankshaft; translating and rotating each of the created subregion three-dimensional point cloud data to superpose each of the subregion three-dimensional point cloud data on a surface shape model of the crankshaft, such that a distance between each of the subregion three-dimensional point cloud data and the surface shape model becomes minimum; and detecting a partial defect such as an underfill of the crankshaft based on a distance between each of the subregion three-dimensional point cloud data after being superposed and the surface shape model.