Eighty-seven patients with carcinoma of oropharynx, tongue and floor of the mouth were examined by means of CT; (TNM criteria); tumor staging was reviewed and compared with that obtained by clinical examination, by endoscopy, at surgery and histology. CT proved to be a reliable technique to detect both the presence of neoplasms, with the exception of very superficial ones, and their deep spread to parapharyngeal space, to muscles of floor of the mouth and prevertebral pterygoid muscles. Lymph node metastases, especially to retropharyngeal nodes, were also clearly demonstrated on CT scans, which indicates this technique as the examination of choice in oropharyngeal and oral cavity tumor staging, for it yields valuable information which can integrate clinical findings.