Objective: To compare the anatomical and visual outcomes of primary idiopathic macular hole surgery using indocyanine green-assisted internal limiting membrane peeling versus no internal limiting membrane peeling., Design: Prospective randomised controlled clinical trial., Setting: University teaching hospital, Hong Kong., Patients: Fifty-one eyes of 49 Chinese patients with primary idiopathic macular hole were studied., Interventions: Patients were randomised to undergo pars plana vitrectomy with indocyanine green-assisted internal limiting membrane peeling (26 eyes) or surgery without internal limiting membrane peeling (25 eyes). Perfluorocarbon gas was used in all cases as internal tamponade., Main Outcome Measures: Primary macular hole closure rate and best-corrected visual acuity., Results: The mean follow-up duration was 12 months (range, 6-23 months). Respectively to the indocyanine green-assisted internal limiting membrane peeling group and non-internal limiting membrane peeling group, the primary anatomical closure rate was 92.3% and 32.0% (P<0.001), whereas improvement in best-corrected visual acuity was 3.7 and 1.5 lines (P=0.002). More eyes in the first group (84.6%) had improvement of 2 or more lines of best-corrected visual acuity after surgery than in the second group (32.0%) [P<0.001]. Multivariate logistic regression showed indocyanine green-assisted internal limiting membrane peeling was the only significant predictor for primary closure of the macular hole (adjusted odds ratio=30.8)., Conclusion: Indocyanine green-assisted internal limiting membrane peeling in idiopathic macular hole surgery results in significantly better anatomical and visual outcomes compared with non-internal limiting membrane peeling in Chinese patients.