We describe the clinical course of a group of patients with primary sclerosing cholangitis who at presentation were diagnosed to have autoimmune hepatitis. The history of one such patient is described in detail. We also compare this atypical sclerosing cholangitis (group I) to typical sclerosing cholangitis (group II) and to autoimmune hepatitis with (group III) and without (group IV) cholestasis. At presentation, mean AST in groups I and III was similar and significantly higher than in group II (P < 0.05). Mean ALP was higher in sclerosing cholangitis than in autoimmune hepatitis but not significantly so. Triaditis was present in all patients in groups I, III, and IV. Piecemeal necrosis and multilobular collapse/fibrosis were equally frequent in groups I, III, and IV. Only the response to corticosteroids helped differentiate among groups. Groups III and IV responded by normalizing AST. In group I, AST improved, but never became normal. As ALP became disproportionately abnormal (ALP-predominant pattern), cholangiography was performed, and the diagnosis of primary sclerosing cholangitis was made in all group I patients. We recommend that cholangiography be performed early in patients with suspected autoimmune hepatitis who partially respond to corticosteroids and develop an ALP-predominant pattern.