The purpose of this study was to evaluate the relationship between the results of laboratory examinations and ultrasonographic findings, especially portal vein hemodynamics in experimentally bile duct ligated dogs. Biliary obstruction was accomplished by surgically occluding the common bile duct in five dogs. All the dogs became visibly jaundiced within 24 hours after surgery. The total protein and albumin/globulin ratio showed a gradual decrease throughout the examination period, while blood urea nitrogen reached its peak in the 6th week and decreased to pre ligation values by the 10th week. Similar trends were noted in the alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, and direct and total bilirubin. Total cholesterol and fasting serum bile acid levels rapidly increased after surgery to peak values between the 2nd and 4th week, and then gradually decreased, but still remained high throughout the experiment period. The portal flow volume and velocity significantly (p0.05) decreased while only a slight increase was noted in the congestion index after bile duct ligation. The cross sectional area of the portal vein changed insignificantly. Bile duct and gallbladder distention was evident within the 1st week after ligation but there was little change in the echogenicity of the liver parenchyma. The results of this study suggest that the determination of Doppler ultrasound parameters of hepatic hemodynamics, especially the portal vein flow indices, may contribute to a better noninvasive assessment of the canine patient with biliary obstructive disease