Purpose: To present the visual and safety outcomes of surgery for primary idiopathic macular holes including predictors of visual acuity and the impact of combined phacovitrectomy surgery. Design: Registry-style, prospective, nonrandomized, observational cohort study. Participants: Patients with idiopathic macular holes undergoing primary surgery. Methods: Surgeons were invited to submit clinical details of all macular hole cases receiving surgery. Baseline demographic and clinical information, and details of surgical intervention were collected. Primary follow-up data were collected at 3 months postoperatively or before revision surgery, and surgeons were also asked to submit data at 12 and 24 months postoperatively. Main Outcome Measures: Visual acuity improvement ≥15 letters and ≥0 letters, change in mean visual acuity, visual acuity ≥70 letters (20/40), retinal detachment, and endophthalmitis. Results: A total of 2455 eyes of 2366 patients were included in the study, and hole closure was achieved in 95.6% of eyes with a single procedure. Mean baseline vision was 48.3 letters. The proportion of successful eyes improving ≥15 letters at 3, 12, and 24 months was 59.1%, 69.4%, and 68.2%, respectively. The mean improvement in acuity at 3, 12, and 24 months was 16.0, 19.2, and 23.6 letters, and 92.4%, 93.4%, and 95.8% improved ≥0 letters at 3, 12, and 24 months, respectively. Eyes receiving SF6 gas had better visual acuities at all time points postoperatively (adjusted effect 3.4, 3.1, and 4.6 letters better at 3, 12, and 24 months vs. longer-acting gas, respectively). Combined phacovitrectomy in phakic eyes was associated with better corrected visual acuity postoperatively (vs. vitrectomy surgery alone), a difference that vanished when eyes went on to have subsequent cataract surgery. The rate of retinal detachment postoperatively was 1.3%, and the odds of detachment were greater in eyes receiving longer-acting gases versus SF6 gas (adjusted odds ratio, 2.2; 95% confidence interval, 1.04–4.77; P = 0.039). There were no reported cases of endophthalmitis. Conclusions: Macular hole surgery substantially improved acuity in approximately two thirds of patients and was seldom associated with loss of vision. SF6 gas was associated with better visual outcomes, an effect that warrants further study.