A method for truing a grinding wheel having a non-straight cylindrical grinding surface. In truing operation, a truing tool is caused to contact different portions of the grinding surface, and relative position of the truing tool is detected when the truing tool contacts the respective portions. Then, a first portion rom which a largest amount of abrasive layer must be removed, and a second portion from which a smallest amount of abrasive layer must be removed are found out. Based upon the detected positions, the radial location of an initial truing start position and a truing operation end position are calculated. The truing tool is initially moved to the initial truing start position, and then traversed from the truing start position along a locus corresponding to a desired final shape of the grinding wheel. The radial location of the truing start position is then shifted in a direction of approaching to the rotational axis of the grinding wheel, and the traverse movement is repeated. When the radial location of the truing start position reaches or exceeds the truing operation end position, the truing operation is stopped.