A review of 200 cases in which routine oral cholecystography was supplemented by tomography is presented. In 69 out of 82 non-visualised gallbladders (NVGB) definite confirmation of gallbladder apthology was obtained. In the poorly functioning gallbladder and the gallbladder obscured by bowel, further information was obtained in 32 out of 56 and 18 out of 26 cases respectively. Tomography proved helpful in localising small filling defects within the gallbladder. Tomography is unlikely to add any extra information to an oral cholecystogram in which a good after fatty meal (AFM) film has been obtained. It is concluded that tomography is a valuable addition to oral cholecystography and increases its accuracy.