Acute cholangitis is a life-threatening emergency, caused by blockage of bile, most commonly by a gallstone (choledocholithiasis). Stasis of bile leads to an infection in the biliary tree known as cholangitis. Cholangitis is graded into 3 categories according to severity of symptoms. The infections are polymicrobial and are predominantly gram-negative rods. Management consists of early initiation of antibiotics and prompt biliary decompression. The biliary tree can be drained by endoscopic retrograde cholangiopancreatography, percutaneous transhepatic cholangiography, rendezvous, or surgical means. Future directions will focus on improving quality of and access to minimally invasive means of clearing the biliary tree.