Purpose: To report the clinical course, management, and outcome of infectious interface keratitis caused by mycobacterium species after laser in situ keratomileusis (LASIK). Design: A small noncomparative interventional case series. Participants: Five eyes in four patients who underwent LASIK in different locations around the world and had culture- positive mycobacterium keratitis develop. Intervention: The LASIK flap was lifted or amputated, samples were submitted for Ziehl-Neelsen acid-fast stain and Lowenstein-Jensen's agar cultures for diagnosis; topical treatment with fortified clarithromycin and amikacin was administered until clinical resolution. Main Outcome Measures: Time periods from onset to diagnosis and from diagnosis to clinical resolution, and the final visual acuity. Results: Onset of symptoms of infection occurred after a mean of 20 days (range, 11 days-6 weeks) after LASIK or an enhancement procedure. Definitive diagnosis was obtained after a mean period of 4.5 weeks (range, 12 days-8 weeks) from onset. Keratitis resolved within 8.4 weeks (range, 1-18 weeks) of treatment with fortified clarithromycin and amikacin. Corticosteroids were found to worsen and prolong the course of disease. In four of five eyes the LASIK flap was amputated. Conclusions: Mycobacterial keratitis is a potentially vision-threatening complication after LASIK, characterized by a long latent period, delayed diagnosis, and a protracted course even under intensive specific antibiotic therapy. Inclusion of specific culture media and staining protocols for mycobacteria, along with aggressive treatment on diagnosis, including lifting or amputating the LASIK flap, culturing, topical fortified clarithromycin and amikacin, while avoiding corticosteroids, may significantly improve resolution of the infection and potentially improve the visual outcome.