Background The vascular anatomy of orbit is highly complex, and the main blood supply to the orbit is via the ophthalmic artery, which is a branch of the internal carotid artery. The purpose of this study was to determine the morphometry of the ophthalmic artery and its branches by superselective angiography in a large series of pediatric patients. Methods We evaluated 134 angiographies performed on children with intraocular retinoblastoma undergoing intra-arterial chemotherapy. The origin, diameter, and angiographic visibility percentages of the ophthalmic artery and its branches were examined according to age group and sex. Results The ophthalmic artery originated 97.8% from the internal carotid artery and 2.2% from the middle meningeal artery. The mean diameter of ophthalmic artery was measured 0.76 ± 0.14 mm in girls, 0.80 ± 0.15 mm in boys and 0.79 ± 0.15 mm in general. The posterior ciliary, lacrimal, inferior muscular, and anterior ethmoidal arteries had a higher angiographic visibility percentages (> 85%) than the other OA branches. Only the diameter of the dorsal nasal artery showed a significant correlation with age. The supratrochlear and posterior ciliary arteries showed statistically significant relationship with sex. Conclusions Present study will make a substantial contribution to the pediatric literature about the ophthalmic artery and its branches. A better understanding of ophthalmic artery morphology can help surgeons and neurointerventional radiologists to avoid possible severe complications during embolization, intra-arterial chemotherapy, cosmetic procedures, endonasal and orbital surgeries.