AIM: To identify risk factors of recurrence of this disorder after intravitreal ranibizumab (IVR) monotherapy. METHODS: Totally 33 eyes of 19 patients who underwent initial IVR treatments for type 1 retinopathy of prematurity (ROP) at our center were retrospectively reviewed between April 1, 2016 and December 31, 2017. Patient demographics, the side of ROP, multiple gestations, Apgar scores, zone, stage, plus disease, postmenstrual age at injection, surfactant therapy, blood transfusion therapy, hemorrhage before IVR, hemorrhage after IVR, gestational diabetes mellitus, pregnancy-induced hypertension, anemia, intraventricular hemorrhage, sepsis, respiratory distress syndrome, carbohemia, and congenital heart defects were recorded. Adjusted hazard ratios (HRs) and 95% confidence intervals were determined after adjusting for potential confounders using multivariate proportional Cox regression. RESULTS: Of the 33 eyes, 12 (36.4%) had ROP recurrences 45.3 (5.1, 50.9)mo after initial IVR treatments. The independent risk factors for ROP recurrences were zone (¢ò vs ¢ñ, HR: 0.056, P=0.003) and gestational diabetes mellitus (no vs yes, HR: 0.095, P<0.001). The mean uncorrected visual acuity for four recurrence eyes was 0.46 logMAR (0.13, 0.70) at 55.0 (51.0, 58.9) mo after the initial IVR treatment. The mean uncorrected visual acuity for 10 eyes without recurrence was 0.46 logMAR (0.19, 0.63) at 48.0 (43.8, 58.4) mo after the initial IVR treatment. CONCLUSION: Two independent risk factors for type 1 ROP recurrence after IVR treatment involving zone¢ñand gestational diabetes mellitus are identified, and the mean uncorrected visual acuity is 0.46 logMAR at 51.0 (44.0, 58.9)mo. The findings of this study are important for follow-up management and for improving the visual function of ROP patients.