PURPOSE: Our objective was to identify a coronary ligament of the knee joint on MR images. MATERIALS AND METHODS: We retrospectively evaluated 50 MR knee studies. Using MR imaging, the thickness and length of the anteroinferior portion of the capsule were measured and compared at the medial and lateral compartments. We also carefully dissected 5 fixed cadaveric knees and took photographs. RESULTS: The thickened synovial membrane(coronary ligament) of the anterior horn of the lateral meniscus appeared as a band of low signal intensity on MR images. On anatomic dissection of the knee joints, the inferior synovial attachment of the lateral meniscus was more redundant than the medial side. CONCLUSION: Anatomic correlation revealed that the coronary ligament contributed to the band-like structure at the anteroinferior aspect of the lateral meniscus.