We evaluated the results of aerobic, anaerobic, and fungal cultures of specimens that had been obtained from multiple sites in thirty patients who had traumatic osteomyelitis with a sinus track. In each patient, we obtained specimens of material from the sinus track; specimens of purulent fluid, of soft tissue, and of bone obtained from curettage; and specimens from the bed of the involved bone. More than one organism grew on culture of the specimens from twenty-one of the patients; more than three organisms, from those of eleven patients; and ten organisms, from those of two patients. The same organisms grew on culture of the specimens from every site in only fourteen (47 per cent) of the thirty patients. We recommend that specimens of material from the sinus track; specimens of purulent material, of soft tissue, and of bone obtained from curettage; and specimens from the bed of the involved bone be obtained for culture before the treatment of chronic osteomyelitis with a draining sinus, so that as many of the infecting organisms as possible will be identified.