Objective To determine the anatomical and visual outcome of indocy anine-green(ICG)-assisted internal limiting membrane(ILM) peeling for idiopathic macular holes. Methods Thirty-one eyes of 31 patients with 3- (14 eyes,45.2%) and 4-staged (17 eyes, 54.8%) primary idiopathic macular holes were analyzed. All the patients underwent the subtotal pars plana vitrectomy with removal of the posterior vitreous. ICG solution with the concentration of 1.25 mg/ml was injected into vitreous cavity. The ILM was stained and removed in a circular fashion of 2 to 3 disc-diameter from the edge of the hole. At the end of the surgery, 14% C-3F-8 mixed gas was used and the patients were required to maintain a prostrate posture for two weeks postoperatively. The mean follow-up duration was 9.1 months. Results The preoperative median visual acuity was 20/200. In the final follow-up, 28 eyes (90.3%) had anatomical restoration of the macular holes, 21 eyes had improvement of two lines or more of visual acuity. There was no direct complication or toxicity related to ICG-assisted ILM peeling except one patient with retinal detachment caused by peripheral retinal hole.Conclusion ICG-assisted retinal ILM removal appears beneficial and safe for primary idiopathic 3- and 4-staged macular holes. (Chin J Ocul Fundus Dis,2003,19:137-140)