PURPOSE: To report a case of Mycobacterium chelonae keratitis after laser in situ keratomileusis successfully treated with medical therapy and flap removal. METHODS: Case report. A 36-year-old white woman in good health developed a paracentral keratitis in her right eye 1 month after bilateral laser in situ keratomileusis. Initial treatment included topical steroids and then intensive Ocuflox (ofloxacin ophthalmic solution; Allergan, Inc, Irvine, California) without success. Cultures were negative. The keratitis worsened, and she was referred to our institution. Interface infiltration was noted, and the flap was lifted to obtain adequate laboratory studies. Cultures were positive for M chelonae. RESULTS: The keratitis was treated with intensive topical amikacin sulfate 1%, topical clarithromycin 1%, and Ciloxan (ciprofloxacin HCL; Alcon Laboratories, Inc, Fort Worth, Texas) with minimal improvement in her clinical condition. She developed a toxic reaction to amikacin 1%. In order to improve antibiotic penetration, the hazy, ulcerated corneal flap was removed, The keratitis then resolved with intensive topical clarithromycin 1% and Ocuflox over 5 weeks. The patient now has visual acuity without correction of 20/50, despite superficial corneal haze. CONCLUSION: M chelonae is a rare and insidious cause of infection after laser in situ keratomileusis. Diagnosis can be difficult and is often delayed. Aggressive medical management, with flap removal, if needed, may lead to resolution of infection. (C) 2000 by Elsevier Science Inc. All rights reserved.