A multifocal progressive infiltration of a corneal graft, which simulated a mycotic keratitis but was repeatedly negative on culture and unresponsive to antibacterial and antifungal therapy, was found upon regrafting to consist primarily of Gram-positive cocci. This bacterial colonization of the corneal graft was associated with epithelialized suture tracks and minimal inflammatory response. The immunosuppressive and bacteriostatic effects of chronic postsurgery low dose steroid and antimicrobial therapy may have played a role in the development of this atypical bacterial infiltrate.