Thirty-three patients suspected of suffering from inflammatory bowel disease were studied. Autologous leucocytes were labelled with indium 111 oxine and re-injected simultaneously with 0.3-0.5 mg of technetium 99m granulocyte-specific monoclonal antibody BW 250/183. Two scans were obtained, the early scan 3-4 h postinjection (p.i.) and the late scan 18-24 h p.i. Using the endoscopy study as standard, the diagnostic accuracy of both agents was determined. Sensitivity, specificity and accuracy of 111In scans was 88.8%, 100.0% and 93.7% at 4 h and 94.7%, 100.0% and 96.9% at 24 h, respectively. Concerning the results using antibodies, the values were 61.1%, 100.0% and 78.1% at 4 h and 78.9%, 92.8% and 84.8% at 24 h, respectively. Segmental analysis showed concordance in 89.3% and 93.3% of the cases at 4 and 24 h, respectively. Though less sensitive and less accurate than scanning employing indium 111 leucocytes, BW 250/183 granulocyte-specific scintigraphy can be used for inflammatory bowel disease diagnosis and localization.