An isolated rupture of the posterior capsule that is caused by a blunt ocular trauma has been rarely reported and is usually detected incidentally during surgery for a complicated cataract. We found an isolated posterior capsule rupture on the third day after trauma in a 25-year-old man who was admitted for the treatment of traumatic hyphema and we performed a phacoemusification and anterior vitrectomy with PC-IOL, implantation because of the traumatic cataract which had progressed after the injury. The PC-IOL was implanted safely into the capsular bag without severe enlargement of the posterior capsular rupture. The break seems to function as a capsulotomy which provides a clear visual axis. We report this case with a review of the literatures.