The growing number of patients undergoing arthroscopy or surgery of the knee for ligamentous injuries has led to a greater need for postoperative imaging because of poor outcome, recurrent symptoms, or a new injury. MRI is the most important imaging method when evaluating the postoperative knee. Radiologists should be familiar with the particular reconstruction technique applied to each examinee, know the spectrum of normal postoperative findings, recognize those findings that may be related to symptoms of failed reconstruction, as well as those lesions that are irrelevant to the previous surgery yet responsible for the new clinical symptoms. In view of the continually evolving surgical techniques, this review presents the current concepts of MRI evaluation of the postoperative knee ligaments based on recent literature reports.