Retinopathy of prematurity (ROP) is a significant cause of blindness in infants. Appropriate therapeutic intervention is essential because retinal detachment due to the progression of ROP is critical to visual function. The intravitreal injection of anti-vascular endothelial growth factor (VEGF) agents has been increasingly applied to inhibit the development and progression of ROP. In this study, we compared the efficacy of single intravitreal bevacizumab (IVB) and ranibizumab (IVR) injections for the treatment of ROP. A total of 39 eyes in 21 patients with severe ROP and IVB (15 eyes of 8 patients) and IVR (24 eyes of 13 patients) were retrospectively reviewed. Patient background, the severity of ROP, and the percentage of cases in which ROP regressed without additional treatment were compared between the two groups. Patient background and ROP severity were not significantly different between the two groups. Recurrence was observed in one eye of one patient in the IVB group, and thirteen eyes in seven patients in the IVR group required additional laser photocoagulation, which was significantly different in the two groups (p < 0.01, Fisher's exact test). In the IVR group, two eyes of two patients underwent vitreous surgery. Compared with IVR, IVB is likely to control the severity of ROP with a single treatment.