CT and MRI are both useful for assessing deep tissue extensions of squamous cell carcinomas of the extracranial head and neck region that are stage T2 or greater. Diagnostic imaging information, in combination with clinical findings, will establish the stage of a primary tumor and the status of regional nodes and will allow a rational treatment plan to be made. Once treatment is completed, a baseline scan 3 to 6 months following treatment is recommended in patients who are at risk for a later recurrence. For most primary tumor sites, MRI will give the most information concerning recurrent disease. Occult primary tumors with regional node metastases present a special set of circumstances. CT or MRI scans are recommended prior to performing random biopsies to search for elusive primary tumors in the upper aerodigestive tract.