Transmission computed tomography (CT), gray-scale ultrasonography, and scinitillation-camera imaging were compared for detection of intrahepatic space-occupying processes. Fifty patients with suspected liver disease were studied by the three modalities. In the 35 cases with confirmed abnormalities, the madalities were rated on a scale of 0 to 5 in terms of their detection value; Each modality was found to have definite advantages and disadvantages. The mean score of ultrasound was highest (3.61), followed by nuclear medicine (3.11) and then CT (2.77). The combination of ultrasound and nuclear medicine identified all lesions, whereas CT alone or in combination with another technique occasionally failed to detect abnormal foci. In the future, the relative efficacy of these procedures may change with improved imaging technology and increased interpreter experience.