BACKGROUND: Reports of incidental gastrointestinal luminal wall thickening (IGILWT) on computed tomography (CT) in patients without gastrointestinal complaints are not rare. Currently there is no consensus about what to do in those cases. The aim of this study was to evaluate the utility of endoscopic study in asymptomatic patients with IGILWT. MATERIAL AND METHODS: Retrospective analysis of data obtained prospectively between September 2004 and March 2007 was carried out. Patients without gastrointestinal symptoms/signs with IGILWT and assessed by endoscopy were included. The endoscopic findings were classified as follows: normal, abnormal or nonspecific. RESULTS: A total of 10,161 abdominal/pelvic CT scans were performed. Thirty-one patients were included (14 women and 17 men). Median age was 59 years (19-84 years). Distribution of IGILWT along the gastrointestinal (GI) tract was as follows: 1 esophagus, 19 stomach, 1 small-bowel, and 10 colon. Endoscopy was normal in 19 cases (61.2%) and abnormal/nonspecific in 12 cases (38.8%). Nine (29%) patients had cancer as a final diagnosis (gastric cancer in six, colon cancer in two, and non-Hodgkin's lymphoma in one). On multivariate analysis hemoglobin <12 g/dl was the only significant variable to predict an abnormal result by endoscopy. CONCLUSION: Endoscopic study is useful in patients with IGILWT. More than one-third of patients with IGILWT have a significant finding by endoscopic evaluation, mainly cancer. Absence of GI symptoms/signs, age or gender are not valid criteria to decide about further endoscopic evaluation.