An image forming apparatus includes a print engine, a sheet transportation unit, a line sensor, and a control unit. The print engine is configured to physically print an image to be printed on a print sheet. The sheet transportation unit is configured to transport the print sheet. The line sensor is arranged along a direction perpendicular to a transportation direction of the print sheet, and configured to detect positions of both end edges of the print sheet. The control unit is configured to (a) determine as a sheet center actual position a center position of the print sheet on the basis of the detected positions of both end edges of the print sheet, and (b) adjust a center position of the image to be printed so as to cause the center position of the image to be printed to agree with the sheet center actual position.