Magnetic resonance imaging (MRI) studies were performed on five patients with acute Maisonneuve fractures. All patients had sustained a twisting injury to their ankles and complained of ankle pain and pain over their proximal fibula. High quality images with excellent visualization of all the ankle ligamentous structures were obtained. MRI showed that the anterior inferior tibiofibular ligament was disrupted in all patients and the posterior inferior tibiofibular ligament was intact in three of five patients. Also, the anterior talofibular ligament was disrupted in all patients and the calcaneofibular ligament was ruptured in two of five patients. This raises the question of whether patients with Maisonneuve fractures have lateral ankle instability at long-term follow-up. Although the superficial deltoid ligament was disrupted in all patients, the deep deltoid ligament was intact in one patient, partially disrupted in one patient, and completely disrupted in three patients. The interosseous ligament was disrupted at the ankle in all patients, while the interosseous membrane was disrupted in the leg in all patients except one. This patient had an intact interosseous membrane despite rupture of the interosseous ligament at the ankle and the presence of a proximal one third fibula fracture.