In-111 leukocyte imaging usually yields images which are interpreted easily. Five potentially misleading cases were noted, however, of over 200 scans performed over a four-year period. These included two cases of bladder visualization without bladder inflammation and three cases of abdominal activity without intra-abdominal abscess or inflammatory bowel disease. Migration of leukocytes from other true pathologic sites and technical factors were responsible for the activity seen. Knowledge of all aspects of the patient's clinical status, including other diagnostic modalities performed, was critical in arriving at the correct diagnosis.