The peroneal long and short tendons are located on the lateral side of the lower leg, travel immediately posterior to the external ankle, and are critical to the function of palmar flexion and external rotation of the foot. A subluxation of the peroneal tendon is a state in which the tendon is out of its normal anatomic position and bounces irregularly to reset. In order to better understand peroneal tendon subluxation, it is necessary to review the relevant anatomical structures. The peroneal long and short tendons are the most important lateral ankle support structures, and these tendons are located on the lateral aspect of the fibula and end at the foot via the posterior aspect of the lateral ankle. Posterior to the lateral ankle the tendons are located in a slightly depressed groove and are encircled by a sheath. The superficial layer of the sheath forms a support band that enhances the fixation of the tendon. There are many causes of peroneal tendon subluxation; some patients have congenital anatomic developmental abnormalities that result in a shallow sulcus on the posterior aspect of the lateral ankle, a relaxed support band, a narrow support band, or a deficiency. However, the most common cause of peroneal tendon subluxation remains ankle sprain. Patients with peroneal tendon subluxation often present with: 1) pain and tenderness around the tendon, 2) localized tendon popping, 3) ankle instability, 4) swelling, and 5) significant ectopic slippage of the tendon. In order to diagnose peroneal tendon subluxation, a combination of physical and impact examinations is required. During the physical examination, attention is paid to whether the peroneal tendon is repeatedly dislocated and reset with ankle motion. x-rays and MRI can help confirm the diagnosis and rule out other pathologies. Dorsal extension and external rotation stress testing of the foot is necessary to diagnose peroneal tendon subluxation. Treatment of peroneal tendon subluxation is divided into conservative treatment and surgical treatment. Conservative treatment includes braking, medication, physical therapy, and specialized bracing. However, in patients with high mobility requirements, conservative treatment is less effective and persistent subluxation will result in rupture of the tendon. Surgical treatment is more appropriate for these patients with high mobility requirements. Surgical treatment involves repairing the tendon’s support band, reconstructing the groove that holds the tendon on the posterior side of the fibula or reconstructing some bony blocking structure.