In a cam grinding method, a common surface of a first cam and a second cam is acquired in a common surface setting step. In a first common surface grinding step performed after a first cam grinding step, traverse movement of a grinding wheel is performed such that the grinding wheel is aligned with an area from the first cam to the second cam while the first cam and the second cam are rotated, and the common surface is ground. In a second common surface grinding step performed after a second cam grinding step, traverse movement of the grinding wheel is performed such that the grinding wheel is aligned with an area from the second cam to the first cam while the first cam and the second cam are rotated, and the common surface is ground.