CT findings in 64 patients of nasopharyngeal cancer are analyzed retrospectively to evaluate the region of origin and the route of spread. RESULTS : 1. The most frequently involved wall is lateral wall, followed by posterior wall and superior wall. 2. There are invasion to parapharyngeal space, retropharyngeal and prevertebral space, carotid space, and masticator space in that order. 3. Involved anatomic sites are Rosenmueller fossa, torus tubarius, E-tube orifice, carotid sheath, soft palate, nasal cavity, skull base, prevertebral muscle and intracranial fossa. 4. Direct extension to intracranial fossa is via sphenoid sinus, foramen lacerum, foramen ovale and jugular foramen in that order. 5. Invasion to prevertebral space leads to intraspinal extension. 6. Cervical lymph node metastasis is found in internal jugular, spinal accessory and retropharyngeal chain in that order. 7. After radiation therapy, most frequent site of recurrence is posterior wall followed by lateral wall superior wall and cervical lymph node, but the presence of recurrence is difficult to determine based on CT only.