Among 650 consecutive radioisotope liver scans, 180 were selected representing all cases in which a pathoanatomical evaluation of the liver was available. The scanning data, the clinical information, and the pathoanatomical diagnosis were reviewed independently, and the results achieved in each group were classified as evidence of normal liver, focal hepatic disease or diffuse hepatic disease. Using pathology for verification scanning had a sensitivity of 97% and a specificity of 90% regarding detection of unspecified liver disease, which was significantly better than clinical setting alone. In diffuse hepatic disease scanning had a sensitivity of 100% and a specificity of 81%, whereas in focal hepatic disease the corresponding figures were 78 and 97%, respectively. Passive hepatic congestion was recognized as a diffuse hepatic disease by scanning, thus representing a source of error in screening for liver disease sensu stricto. Scanning, apart from being a rapid and simple procedure without significant inconvenience to the patient, is a very accurate diagnostic tool that deserves more recognition in clinical departments.