Purpose: To describe the anatomic and visual outcomes of eyes undergoing reoperation after failed primary surgery for idiopathic macular hole. Design: Prospective registry study. Participants: One hundred three patients who had undergone failed macular hole surgery. Methods: Unclosed idiopathic macular holes were identified from a large national prospective registry run by the Australian and New Zealand Society of Retinal Specialists. Unclosed idiopathic macular holes were defined as idiopathic macular holes that underwent vitrectomy surgery for the first time, but were never observed to close in the postoperative period. Surgeons were contacted to submit retrospectively details of subsequent management and long-term outcome of these eyes. Main Outcome Measures: Macular hole closure; visual acuity (VA) change relative to baseline at 3, 12, and 24 months; and hole size at all time points. Results: One hundred three patients with failed macular hole surgery were identified, among whom 53 underwent reoperation, 49 did not, and 1 was lost to follow-up. Macular hole closure was achieved in 45 of 53 patients (85%) undergoing revision surgery. Mean change in VA from baseline in eyes undergoing revision surgery versus eyes that did not was +2.8 letters versus −1.9 letters at 3 months (P = 0.278), +8.2 letters versus −1.9 letters at 12 months (P = 0.167), and +18.3 letters versus −3.4 letters at 24 months (P = 0.022). Thirty-six percent of eyes with reoperated holes showed improved VA of 15 letters or more at 3 months after operation, increasing to 48% at 12 months and 65% at 2 years. Before revision surgery, mean macular hole size was observed to increase from 483 μm to 562 μm after failed primary surgery (P = 0.046). Conclusions: In eyes undergoing revision surgery, reoperation for unclosed macular holes was significantly better than observation, although these visual gains took some time to occur. The surgical success rate was lower than that for primary idiopathic macular hole. The selection criteria for revision surgery need to be defined.