The intrahepatic duct stones are prevalent in east Asia and pose serious health problem because of the frequent recurrence and often associated suppurative cholangitis. Accurate diagnosis and localization of intrahepatic duct stones are essential to good prog-nosis and selection of adequate therapeutic methods. We studied 112 cases of intrahepatic duct stones diagnosed with ultrasound and confirmed by operation or other radiologic studies for recent 3 years from May 1986 to May 1989 at Department of Radiology National Medical Center and analysed ultrasonographic findings. The results were as follows:1. Among 112 cases 73(65%) were female 39(35%) were male with predominacy in 5th decade. 2. The most common location of intrahepatic duct stones was left intrahepatic duct in 48 cases (43%) followed by right intrahepatic duct in 42 cases (37.5%) and both intrahepatic ducts in 22 cases (19.5%) In respect of segmental distribution left lateral segment is the most common location (53 cases 34% followed by right posterior segment(43 cases 27%). 3. Ultrasonographic findings were as follows: nodular pattern is the most common (59 cases 53%) followed by tubular or linear impac-ted pattern (23 cases 20%) irregular heterogenous conglomerated mass (13 cases 12%) smooth homogenous single mass(10 cases 9%) and mixed (7cases 6%) in orders. Ductal dilatations were classified by diffuse dilatation (16 cases 14%) localized dilatation (50 cases 45%) and no dilatation (46 cases 41%) Many of the tubular impacted stones showed no ductal dilatation and single mass showed ductal dilatations in all cases. 4. In 53 cases (47%) combined extrahepatic duct stones were present. 5. As associated findings liver cirrhosis in 11 cases (10%) cholangitis in 9 case (8%) cholecystitis in 7 cases (6%) hepatic and pericholangitic abscess in 3 cases (3%) and CBD cancer GB cancer acute pancreatitis in 2 cases (2%) respectively.