The distal radioulnar joint (DRUJ) is a very important component of normal forearm rotation. Any bony incongruence of the DRUJ could result in the blockade of forearm rotation. Meanwhile, isolated ulnar head fracture is a rare condition among all reported wrist injuries. In this report, we present a case featuring the blockade of forearm rotation as a result of neglected ulnar head fracture and malunion. Satisfactory results with restored forearm rotation are achieved after performing ulnar head corrective osteotomy.