To investigate the causes of, pathologic changes associated with, and treatment results after traumatic peroneal tendon subluxation or dislocation, we reviewed 11 cases in 10 patients at a mean followup of 29 months. We also describe a technique of superior peroneal retinacular repair combined with fibular rotational osteotomy. Excellent clinical and functional results were achieved in 9 of the 11 cases, enabling the patients to return to previous competitive sports by 3 months. There was one persisting subluxation that required further surgery. Another ankle, with chronic sepsis from previous surgery and documented degeneration of the ankle joint, had a recurrence of the infection and sequestration of the osteotomized fragment. The personal tendons, however, remained stabilized by the resultant scar tissue. We conclude that superior peroneal retinacular repair, with or without fibular rotational osteotomy, is a successful technique in treating both acute and recurrent instability of the peroneal tendons. It can be combined with a Bröstrom repair when there is concurrent peroneal tendon and anterolateral ankle instability. Peroneal tenosynovitis and tendon splitting were commonly found at operation, especially in cases of recurrent instability. The degree of pathologic change in the tendon did not affect the clinical result.