A recipient of a renal homograft developed disseminated infection caused by Mycobacterium kansaii. He initially presented with cellulitis and abscesses in one foot, and was thought to have a pyogenic bacterial infection. The daily administration of prednisone and azathioprine appears to have prevented the typical cell-mediated granulomatous reaction to mycobacterial infection and to have contributed to the patient's atypical inflammatory response. A switch to alternate-day prednisone combined with antimycobacterial medication resulted in rapid healing without rejection of the homograft.