AIM: To evaluate the effect of intravitreal ranibizumab injection for retinopathy of prematurity (ROP) in Zone II Stage 3+. METHODS: Data was collected for ROP patients with Zone II Stage 3+ who received intravitreal ranibizumab injections between October 2014 and Janu-ary 2017 at the Department of Ophthalmology in our hospital. No prior laser or other intravitreal treatment was done. Prior to the intervention and at each follow-up visit, fundus examination was performed. Gestational age at birth, sex, birth weight, ROP zone, ROP stage, post menstrual age (PMA) at treatment, and follow-up pe-riod were recorded. The final clinical status of the retina was evaluated for each patient. The primary outcome mea-sures included ROP recurrences requiring re-treatment, complete or incomplete peripheral vascularization. RESULTS: Eighty-six eyes of 46 premature infants with Zone II Stage 3+ ROP were enrolled in the study. The mean gestational age at birth was 28.18±1.67 (range: 25 to 33)wk and the mean birth weight was 1070.57±226.85 (range: 720.00 to 1650.00) g. The mean PMA at treatment was 38.32±2.99 (range: 32.29 to 46.00)wk. Seventy-one eyes (82.56%) were treated success-fully with intravitreal ranibizumab as monotherapy. Fifteen eyes (17.44%) developed recurrent disease. The mean interval between the treatment and retreatment was 5.96±3.22 (range: 1.86 to 11.71)wk. All eyes vascularized into zone III at the end of the study and among them 62 eyes (72.09%) achieved complete vascu-larization. CONCLUSION: Intravitreal ranibizumab injection is an effective treatment in Zone II Stage 3+ ROP patients. More patients with longer follow-up duration are necessary to confirm the safety and efficacy of this treatment.