Acalculous hemorrhagic cholecystitis is a rare complication of acute cholecystitis and is associated with a high mortality rate. We present a case of acalculous hemorrhagic cholecystitis with hematoma in the gallbladder lumen, which was diagnosed using magnetic resonance imaging (MRI). The T1- & T2-weighted MRI revealed gallbladder distension with a hypointense intraluminal hematoma. The excellent tissue contrast provided by MRI is useful for detecting hematomas in the cases of hemorrhagic cholecystitis.