A retrospective review was performed of the results of operative treatment of stenosing tenosynovitis of the flexor hallucis longus tendon or posterior impingement syndrome, or both, in thirty-seven dancers (forty-one operations). The average duration of follow-up was seven years (range, two to thirteen years). The results were assessed with use of a questionnaire for all patients, and a clinical evaluation was performed for twenty-one patients (twenty-two ankles). Twenty-six operations were performed for tendinitis and posterior impingement; nine, for isolated tendinitis; and six, for isolated posterior impingement syndrome. A medial incision was used in thirty-three procedures; a lateral incision, in six; an anterior and a medial incision, in one; and a lateral and a medial incision, in one. Thirty ankles had a good or excellent result; six, a fair result; and four, a poor result. (The result of the second procedure on an ankle that was operated on twice was not included.) The result was good or excellent for twenty-eight of the thirty-four ankles in professional dancers, compared with only two of the six ankles in amateur dancers.