The computed tomographic and sonographic findings of 26 patients with gallbladder carcinoma were reviewed, and the problems and pitfalls encountered with these imaging techniques are discussed. The most common finding, a mass filling or replacing the gallbladder, was seen in 42% of the patients. A mass protruding into the gallbladder was seen in 23%, and diffuse asymmetric thickening of the gallbladder wall in 15%. Recommendations are made to avoid some of the diagnostic problems encountered. With careful and meticulous technique early carcinoma of the gallbladder may be detected with greater frequency by cross-sectional imaging techniques.