Congenital entropion is a rare eyelid anomaly that can cause chronic corneal erosions or ulceration. The diagnosis may be easily overlooked by both the pediatrician and the ophthalmologist, particularly when the lids are tightly closed in the crying child. We present three cases of congenital entropion associated with corneal ulceration. Each patient underwent a complete ophthalmologic examination. Examination under anesthesia, including corneal scrapings for culture and photography, was performed before surgical repair of the entropion. There were two cases of lower lid entropion and one case of upper lid entropion. In all three cases symptoms were present since birth, and the diagnosis was overlooked by the treating pediatrician. Corneal ulceration ultimately developed in all three cases. Cultures revealedStaphylococcus aureusin one case, and coagulase negativeStaphylococcusin another case. Cultures were negative in one case. In all three patients the ulcers healed rapidly after surgical entropion repair. Congenital upper or lower lid entropion is an uncommon condition that does not spontaneously improve and is an important cause of corneal ulceration in infants. Recognition of this condition is often difficult, and early surgical intervention to repair the lid deformity may help to avoid permanent corneal scarring and visual loss