Pseudoaneurysm or false aneurysm is one of the late complication of a missed or untreated arterial injury. Most traumatic aneurysms in the extremities are false, and they are usually caused by penetrating trauma. The diagnosis of pseudoaneurysm is suggested by the presence of one or more of the followings: an expanding ill defined mass with or without pulsation, a bruit, pain, paresthesia or paralysis due to nerve compression, an absent peripheral pulse, or signs of ischemia. Although plain radiographs may demonstrate a nonspecific soft tissue mass, arteriography is essential in defining the false aneurysm or aneurysms and differentiating them from other soft-tissue masses. We are reporting the case of a patient who had a false aneurysm of the posterior tibial artery after open fracture of tibial shaft.