Spontaneous intestinal hematoma is a rare complication of anticoagulant therapy. The authors reported three cases of intramural and submucosal small bowel hematoma resulting from warfarin administration. The first patient presented with abdominal pain, had intramural hematoma at jejunum, the most common site of intramural small bowel hematoma. Another patient who had submucosal duodenal hematoma presented with massive upper gastrointestinal bleeding, a rare manifestation of small bowel hematoma. The third patient presented with intramural ileal hematoma that caused abdominal pain and palpable mass after a short period of warfarin therapy. Typical findings on abdominal computerized tomography yielded the diagnosis. All patients rapidly improved after conservative treatment. The history of anticoagulant use with prolonged INR value in patients presented with abdominal pain should alert physicians to search for this entity. It is extremely important to recognize this syndrome in order to avoid an unnecessary operation since the outcome is usually excellent after conservative treatment.