Purpose: We sought to evaluate the effects of intraoperative adjunctive autologous serum in idiopathic fullthickness macular hole surgeries, and to compare the surgical outcomes with a no-serum control group. Methods: In this retrospective, case-control study, 38 consecutive eyes received vitrectomy with internal limiting membrane removal for idiopathic full-thickness macular holes. Two groups were created according to the use of autologous serum. Outcome measures were visual acuity (VA), closure of the macular hole confirmed by optical coherence tomography, and surgical complications. Results: Anatomical closure of the macular hole was achieved in 18 of 19 eyes (94.7%) in the vitrectomy with the autologous serum group, and in 18 of 19 eyes (94.7%) in the control group. The closure rates did not differ significantly between 2 groups (P = 1.000; the Fisher's exact test). At the final follow-up, the mean logMAR VA improved significantly in both groups (SD, standard deviation) [from 1.08 (0.21) to 0.47 (0.21) in vitrectomy with the serum group and from 1.01 (0.32) to 0.44 (0.30) in the control group (both P < 0.001; 2 tailed, paired t test)]. There was no significant difference between these 2 groups in terms of visual outcomes (P = 0.738; 2-tailed t test). There were no surgical complications, such as retinal detachment and endophthalmitis. Conclusions: The outcome of macular hole surgery did not differ both anatomically and functionally regardless of the use of adjuvant autologous serum. There seemed to be no additive effect with autologous serum.