The administration of metronidazole is generally effective to treat amebic colitis. Fulminant amebic colitis is relatively rare, and it is associated with a high mortality rate. Three cases of fulminant amebic colitis were diagnosed in our hospital between 1993 and 2014. One of these patients died despite our efforts. Amebic colitis often presents with no obvious risk factors and with atypical clinical symptoms. Therefore, the diagnosis of amebic colitis can be difficult. Early diagnosis is the most important factor in successful treatment of fulminant amebic colitis. The present cases demonstrate that it is important to consider the possibility of amebic colitis during evaluation of the acute abdomen.