The knowledge of the location and extent of bowel involment and disease activity can be an important aspect on the evaluation of inflammatory bowel disease. Thirty five patients of Crohn's disease (CD) have been studied in this sense. We performed a total of 44 scintigraphic examinations using 99mTc-HMPAO labeled leukocytes and the results were compared with several clinical-biological indexes and with radiology and endoscopy. The Tc scan was the most sensitive (84.3%) and specific (100%) activity index and showed an excellent correlation with radiology and/or endoscopy in the assessment of extent of disease. Leukocyte scanning brought useful information for the management of stenosis in CD.