The features of nonsuppurative cholangitis were studied in liver biopsy specimens from 185 patients with chronic active hepatitis (CAH), 280 patients with primary biliary cirrhosis (PBC), and 55 patients with primary sclerosing cholangitis (PSC). Specimens from patients with other liver diseases in which the presence of nonsuppurative cholangitis had been recorded were also studied. We identified four types of nonsuppurative cholangitis: granulomatous cholangitis, lymphoid cholangitis, fibrous cholangitis, and pleomorphic cholangitis. Granulomatous cholangitis almost always seemed to be destructive; the other types were either destructive or nondestructive. Granulomatous cholangitis was, for all practical purposes, diagnostic of PBC and the obliterative form of fibrous cholangitis was similarly diagnostic for the hepatic manifestations of PSC in adults and paucity of intrahepatic bile ducts in infants. All other types of cholangitis were found in CAH, PBC, PSC, and other liver diseases. Thus, the term "nonsuppurative cholangitis" describes a spectrum of morphologic lesions that differ in incidence, morphogenesis, usefulness for liver biopsy diagnosis, and, probably, pathogenesis.