PURPOSE: We designed this study to determine the potentiality of the conventional CT in the diagnosis of submandibular gland lesions, especially in solving the diagnostic difficulty between neoplasm and inflammation. MATERIALS AND METHODS: We performed retrospective study of 35 patients and 2 of them had bilateral lesion of chronic inflammation, hence we analysed 37 cases of submandibular gland lesions. There were 9 cases of tumor (including 1 basal cell carcinoma, and 8 pleomorphic adenomas), 22 cases of chronic inflammation, and 6 cases of acute inflammation. CT scans were evaluated for the degree of enlargement (graded as iso, mild or marked enlargement), pattern of contrast enhancement, contour deformity of the gland, and several other items. RESULTS: Neoplastic masses showed more marked enlargement of the gland (77%) than chronic inflammation (22%). Degree of enhancement showed no difference among the lesions. Enhancement pattern was more inhomogeneous in neoplasm (80%) than in chronic inflammation (5%). Deformity of the natural contour of the gland was more frequent in neoplasm (all of 9 cases) than in chronic inflammation (32%). Acute inflammation showed internal low attenuation probably by abscess formation (3/6 cases) and overlying soft tissue swelling (all of 6 cases), and the age of patients was characteristically younger than other diseases (mean, 9 years). Several findings were more specific to diseases, such as dystrophic calcifications to pleomorphic adenoma (37%) and calculi with or without ductal dilatation to chronic inflammation (45%). CONCLUSION: Pre and postcontrast enhanced CT scan can serve as a predictor of pathologic nature of the submandibular gland lesions.