A case of Mycobacterium chelonae keratitis is described. As with any infective keratitis, appropriate treatment depends upon rapid and accurate microbiological assessment of corneal scraping. Acid-fast stains such as Ziehl-Nielson should be performed, particularly in chronic corneal ulcers, as only these stains will distinguish mycobacteria from the more common diphtheroid organisms. The mycobacterium chelonae organism was sensitive only to tetracyclines.