Budd-Chiari syndrome, a well known entity, is often difficult to diagnose, mostly due to the nonspecificity of its symptomatology. Radiocolloid liver scans were evaluated in eight cases of this disease, proven by surgical biopsy. Five cases showed the "classic" scintigraphic pattern of caudate lobe hypertrophy (62.5%), and other abnormalities observed included segmental hepatic insufficiency, diffuse hepatic insufficiency, and relative hypertrophy of both the caudate lobe and a portion of the parenchyma of segment VI (one case each). An experimental study of hepatic venous drainage performed on livers at autopsy revealed four groups of accessory hepatic veins in addition to the main hepatic veins. The occlusion of various parts of this drainage appears to relate to the various scintigraphic patterns that were encountered in patients with Budd-Chiari syndrome. A review of the literature revealed three additional patterns previously reported in association with Budd-Chiari syndrome (normal scan, diffuse hepatomegaly, and multiple filling defects). If all these variations are appreciated, liver scanning can be a valuable screening tool for Budd-Chiari syndrome and may also serve as a noninvasive means of follow-up.