Acute obstructive suppurative cholangitis is a pathologic condition that does not exhibit a distinct clinical presentation and severity. The mere presence of suppuration in an obstructed biliary tree may not be associated with overwhelming sepsis. Urgent therapeutic intervention is mandatory only in those patients with clinically severe and progressive disease, for which the term "severe acute cholangitis" seems more appropriate. Acute cholangitis develops when an obstructed biliary tree becomes colonized by bacteria. Bacterial colonization is more frequent with choledocholithiasis than with malignant strictures, with choledocholithiasis being the most common cause of acute cholangitis. However, the increased use of non-operative manipulation of the biliary tree results in more patients with acute cholangitis secondary to malignant obstruction, since the risk of acute cholangitis after direct cholangiogram is higher with malignant obstruction. Not only is there a higher risk of acute cholangitis but the systemic sepsis tends to be more severe with malignant obstruction because of the problem of incomplete drainage. When cholangitis develops in the presence of a stent, few of these patients have local symptoms such as abdominal pain or jaundice.