PURPOSE: This study was designed to compare the CT findings and clinical manifestations in children and adolescents with acute sialadenitis according to the involved salivary glands. MATERIALS AND METHODS: The study included fifty children and adolescents (34 boys, 16 girls) with acute sialadenitis that was diagnosed during the past five years. All of the subjects were divided into three groups: group I (parotid gland involvement, n = 16), group II (submandibular gland involvement, n = 20) and group III (involvement of both glands, n = 14). We analyzed the presence of an abscess, sialolith, bilaterality, cellulitis and lymphadenopathy on CT scans. The analyzed clinical data were age, sex, lymphadenopathy, pain, swelling, presence of a mass, tonsillitis, treatment period and surgical treatment if it was performed. RESULTS: The presence of an abscess, sialolith, cellulitis, swelling, age, presence of a palpable mass and treatment period were statistically significant factors for the patients in the three groups. An abscess was combined only in group I patients. There was a high rate of sialolith in group II patients and cellulitis in group III patients as seen on CT scans. Swelling in group II patients and group III patients and the presence of a palpable mass in group I patients were identified as clinical manifestations. Age was younger in group I patients (mean age, 5.3 years) than in group II patients (mean age, 12.9 years) and group III patients (mean age, 15.2 years). The treatment period was longer for group I patients. CONCLUSION: For acute sialadenitis in children and adolescents, age, presence of an abscess, sialolith, cellulitis, swelling, presence of a palpable mass and treatment period were different according to the involved salivary glands.