An image forming apparatus for preventing sheet jams and displacement of image formation when forming images on both front and rear sides is provided. The apparatus includes first and second width regulation mechanisms, a reverse transport mechanism and a link mechanism. The first width regulation mechanism is provided within a sheet holding chamber, and is movable with respect to a center of an image formation range of an image forming unit. The reverse transport mechanism is configured to turn the sheet from a first side to a second side upon the first side passing through the image forming unit. The second width regulation mechanism, provided within the reverse transport mechanism, is movable in the width direction. The link mechanism is provided between the first and second width regulation mechanisms for changing a position of the second width regulation mechanism in association with position change of the first width regulation mechanism.