Scintigraphy with Tc-99m labeled antigranulocyte antibodies (BW 250/183 MoABs) was performed in 32 patients with suspected appendicitis. Abdominal imaging (planar/SPECT) was performed 2 hours after injection of the tracer. All patients also had surgery and a histologic examination of the resected tissue. Of the patients, 17 suffered from "acute appendicitis" and 12 had right positive scans (sensitivity = 70.6%). In 15 patients, acute appendicitis could have been ruled out, and in 11 of these cases the scan was true negative (specificity = 73.3%). The overall accuracy was 71.8% (23/32 cases). The use of Tc-99m antigranulocyte MoABs may overcome the problems associated with the Tc-99m HMPAO granulocyte and In-111 oxine approaches, which include nonspecific intestinal activity or the lack of timeliness. The use of Tc-99m labeled antigranulocyte antibodies is suitable as an emergency procedure and may play a role in the management of patients with suspected appendicitis.