Congenital megalocornea is a bilateral enlargement of the cornea's diameter that can be associated with trabecula and/or iris dysgenesis. This condition predisposes the patient to glaucoma. The physiopathology is poorly understood and may be related to lens induction during embryological development of the anterior of the eye. X-linked genetic transmission is found in 50% of cases, autosomal transmission in 40%, and sporadic transmission in the remaining 10%. Diagnosis is based on a thorough examination of the child's eye, often with general anesthesia. Different clinical aspects can be observed: simple megalocornea without ocular or systemic anomalies, megalocornea with ocular and/or systemic anomalies as well as multiple malformation syndromes, dermatological diseases, skeletal diseases, and genetic or chromosomic diseases. A systematic general pediatric examination is therefore necessary. Congenital megalocornea must be considered, first of all, as a differential diagnosis of primary congenital glaucoma and all of its etiologies. Treatment of associated ocular diseases, the search for an association with systemic diseases, and follow-up for the rest of the patient's life are indispensable.