A total of 28 patients (29 eyes) with stage 2-4 idiopathic full-thickness macular holes were treated with the use of autologous serum. Autologous serum (20-30 microL) was placed over each macular hole followed by injection of 16% perfluoropropane gas. Postoperatively, 28 eyes (97%) had flattening of the macular hole, and the hole could not be detected in 27 eyes (93%). Twenty-two eyes (76%) showed visual acuity improvement by at least two lines or more. Preoperative factors such as good visual acuity, earlier stage, and younger age were correlated with postoperative good visual acuity. These results suggest that autologous serum is beneficial in the treatment of full-thickness macular holes.