 Anaplastic thyroid cancers are rare, aggressive tumors. Standard treatment options include surgery and chemoradiation. Few treatment options are available once metastases develop. Recent data suggest that Imatinib Gleevec may be advantageous in this patient population. Patients who have been treated for anaplastic thyroid cancer with chemoradiation or surgery who develop recurrent or metastatic disease outside of the field of radiation are eligible. Patients will be treated with Imatinib 400 mg two times a day for eight weeks, followed by radiologic assessment. Patients will be treated until disease progression or a complete response is obtained. 