We tracked cultures submitted to a laboratory in 2004 in which mycobacteria other than Mycobacterium tuberculosis or Mycobacterium avium complex were grown (n = 11). We reviewed clinical information, other mycobacterial cultures, and radiologic findings. We measured the time from specimen submission to first growth and to final species identification. We assessed the response to this information based on notes, laboratory tests, consultations, and radiology studies. The median time to identification was 68 days (47-292 days). In 5 cases, the clinician failed to retrieve the data, and in 3 of these cases, there was a resultant loss of opportunity to treat. In 3 cases, the laboratory never reported a definitive species, and in 3 cases, the culture results were clinically unimportant. We show that the results of positive cultures of these mycobacteria are effectively lost because they are not available in a timely fashion, and even when available, the results are overlooked.