Botulinum toxin A injection is a safe alternative procedure to surgery in the management of different types of strabismus. Serious complications such as globe perforation are rare in expert hands. The authors report a case of a child known to have a muscle-eye-brain disease with high myopia who developed endophthalmitis following inadvertent penetrating intraocular botulinum toxin A injection for strabismus correction. To their knowledge, this serious complication after penetrating botulinum toxin A injection has not been previously reported. [J Pediatr Ophthalmol Strabismus. 2023;60(2):e8-e10.].