The corneal biopsy is a diagnostic procedure not often performed, however is an important skill in the management of more complex keratitis. Corneal scraping is not useful in these cases as the infiltrate is located deeper in the stroma. A 24 washout period of all antimicrobials improves the yield of organisms and reduces antibiotic contamination of the specimen. This video describes the steps to perform an effective, corneal biopsy as safely as possible, avoiding perforation.