PURPOSE To report national case-finding results for nontuberculous mycobacterial keratitis and describe its association with laser in situ keratomileusis (LASIK). DESIGN Enhanced passive disease reporting. METHODS In April 2001, we investigated a California cluster of Mycobacterium chelonae keratitis associated with hyperopic LASIK using a contact lens mask. To identify other possibly related cases, the American Academy of Ophthalmology e-mailed its members asking them to report recent cases of nontuberculous mycobacterial keratitis to the Centers for Disease Control and Prevention. RESULTS Forty-three additional cases of keratitis were reported (onsets between August 2000 and June 2001). Of these, 31 occurred as part of two unrelated LASIK-associated outbreaks. The 12 other reported cases occurred in sporadic fashion. Of the latter cases, 4 were associated with LASIK surgery. None of the reported cases were related to the M. chelonae cluster in California. CONCLUSIONS Laser in situ keratomileusis-associated keratitis with nontuberculous mycobacteria may be more common than previously known.