Rectus abdominis syndrome is the abdominal pain which occurs in the distribution of the medial or lateral cutaneous branch of the 7~12th intercostal nerves. It is frequently cause that results in unnecessary pain and expense to patient. The physical examination is difficult because of severe abdominal pain. We must have attention to the possibility that patients with abdominal pain, in whom no intra- abdominal cause is founded, may suffer from this presumed nerve entrapment syndrome. If we can find the cause of pain in the abdominal rectus muscle, no evaluation and surgery are required and therapy can be simple.