PURPOSE: To describe a case of congenital entropion presenting with ulcerative keratitis that was successfully treated with a single injection of botulinum toxin. DESIGN: Interventional case report. METHODS: A 3-week-old female infant with a corneal ulcer of the left eye since birth presented for evaluation. She was found to have entropion of the left lower lid. The pretarsal orbicularis muscle was injected with 5 units of botulinum toxin. RESULTS: Four days after treatment, the entropion had resolved and the corneal epithelial defect had healed. There was no recurrence of the entropion 7 months after botulinum toxin injection. CONCLUSIONS: Injection of botulinum toxin can effectively treat certain cases of congenital entropion. (C) 2004 by Elsevier Inc. All rights reserved.