Acquired hemophilia is rare and the presentation of a spontaneous hematoma on the floor of the mouth is very unusual. We present an unusual case of an older adultpatient who presented a spontaneous hematoma on the floor of the mouth without apparent cause, with acquired hemophilia A. The data source for the case was the patient's medical history. When reviewing the literature only 13 reported cases of upper airway bleeding have been reported in patients with diagnosed acquired hemophilia, withmales the most affected and the mean age of patients being 69.53 years. Differential diagnoses, imaging, radiographs, scans and laboratory tests help to establish a timely diagnosis and act quickly.