A 9-month-old female patient presenting with right eye esotropia. She had history of prematurity (33 weeks of gestation) and septum pellucidum agenesis detected in the transfontanelar ultrasound. Teller Visual Acuity Test was 20/1200 in the right eye (RE) and 20/80 in the left eye (LE). Fundoscopy revealed RE optic nerve hypoplasia. MRI confirmed the absence of the septum pellucidum and showed reduction in the orbital and intracranial right optic nerve diameter. No other central nervous system abnormalities were found. Diagnosis of septo-optic dysplasia was made.