Five cases of histologically proven polymorphic reticulosis were examined with computed tomography (CT). CT findings were mucosal thickening along the septal and lateral walls of the nasal cavities (n=4), obliteration of the contour of the nasopharynx(n=4), involvement of the paranasal sinuses (n=2), destruction of the nasal septum and/or sinus walls (n=3) and mass in the palate, tonsil or neck (n=1). CT examination was helpful in determining the extent of the disease in the nasal cavity and paranasal sinuses. However, lesions in the palate and tonsils could not be easily evaluated with CT. CT findings of polymorphic reticulosis are nonspecific and granulomatous diseases may show similar CT findings.