We investigated the cholangiographic appearance of intrahepatic bile ducts in 56 liver transplants and correlated the findings with biopsy evidence of acute rejection and other histologic diagnoses. Mild to moderate narrowing, stretching, separation, and poor filling of the bile ducts were common. Narrowing was present in 69 (92%) of 75 studies and was at least moderate in degree in 14 (19%). Duct separation was seen on 39 (58%) of 67 cholangiograms and was usually mild but was more pronounced in 10 (15%). In 22 (25%) of 89 studies, 10 or fewer branch ducts were filled. Cholangiographic abnormalities were more marked in patients with biopsy diagnoses of moderate-severe and partially treated acute rejection than with findings of mild rejection or nonspecific histology. Portal tract cellular infiltration and edema, liver swelling and, possibly, loss of small bile ducts correlated with the radiologic changes. However, the severity of the radiographic changes varied in all histologic categories. Acute rejection contributes to intrahepatic duct narrowing, separation, and poor filling on cholangiography in liver transplants, but the cause of the changes is probably multifactorial. Cholangiography is limited as a test for rejection and other hepatic parenchymal abnormalities in individual patients, but it may provide evidence supporting the need for liver biopsy in the evaluation of hepatic dysfunction after transplantation.