Liver scans of 72 patients with suspected malignant disease were evaluated to determine the accuracy of the investigation in detecting disease, including metastases and also its use to the referring surgeon. A comparison between the liver scan result and clinical and biochemical findings was also made. The liver scan had an overall accuracy of 83% in diagnosing metastases, compared with 64% for the serum alkaline phosphatase (SAP) level and was more useful clinically than the SAP level. Careful classification of the liver scan patterns allowed more consistent interpretation and improved the specificity of the diagnostic information obtained. Clinical assessment of liver and spleen size by abdominal palpation was unreliable and occasionally misleading.