In order to evaluate the scintigraphic features of choledochal cyst and these diagnostic value, authors investigated the findings of fourteen patients with choledochal cyst undergone hepatobiliary scan with Tc- 99m-DISIDA before surgery. Five cases demonstrated the decreased hepatic uptake at 5-minute image of which four cases revealed severe jaundice. Seven cases demonstrated visualization of the cystic dilated common bile duct within 1 hour after injection. Two cases showed the cyst activity between 1 and 12 hour, but the cyst activity was not visible in five cases. Nonvisualization of the gall bladder was noted in ten cases, while four cases demonstrated visualization of the gall bladder within 1 hour. The time of visualization of gut activity was variably delayed. The intestinal activity was found in three cases within 1 hour and appeared in three cases between 1 and 2 hours and eight cases showed no visible gut activity. In four cases, intrahepatic ductal prominence was visible on the scintigram. Seven cases showed early and persistent accumulation of tracer in the common bile duct. Three cases showed persistent photon-deficient area in the gall bladder region. Two cases showed early photon- deficient area around gall bladder region with progressive accumulation of tracer in the same region. Two cases showed no evidence of activity in the biliary tract but noted late excretion into the sma11 intestine. We concluded that hepatobiliary scan using Tc-99m-DISIDA is a noninvasive test useful in the eva1uation and the diagnosis of choledochal cyst.