BACKGROUND: Surgeon physical examination is often used to monitor for hernia recurrence in clinical and research settings, despite a lack of information on its effectiveness. This study aims to compare surgeon-reviewed CT with surgeon physical examination for the detection of incisional hernia. STUDY DESIGN: General surgery patients with an earlier abdominal operation and a recent viewable CT scan of the abdomen and pelvis were enrolled prospectively. Patients with a stoma, fistula, or softtissue infection were excluded. Surgeon-reviewed CT was treated as the gold standard. Patients were stratified by body mass index into nonobese (body mass index <30) and obese groups. Testing characteristics and real-world performance, including positive predictive value and negative predictive value, were calculated. RESULTS: One hundred and eighty-one patients (mean age 54 years, 68% female) were enrolled. Hernia prevalence was 55%. Mean area of hernias was 44.6 cm 2. Surgeon physical examination had a low sensitivity (77%) and negative predictive value (77%). This difference was more pronounced in obese patients, with sensitivity of 73% and negative predictive value 69%. CONCLUSIONS: Surgeon physical examination is inferior to CT for detection of incisional hernia, and fails to detect approximately 23% of hernias. In obese patients, 31% of hernias are missed by surgeon physical examination. This has important implications for clinical follow-up and design of studies evaluating hernia recurrence, as ascertainment of this result must be reliable and accurate. (C) 2014 by the American College of Surgeons