The purpose of our study is to assess the usefulness of a scoring system for ultrasonography using a high-frequency transducer as a non-invasive examination in the differential diagnosis of cervical malignant lymphoma from benign lymphadenitis. Ultrasonography was performed with a real-time linear scanner using 7.5 and/or 11 MHz probes in 66 patients who were presented with cervical lymphadenopathy and were suspected to have malignant lymphoma. Thereafter, a surgical biopsy was performed for histopathological diagnosis, revealing 49 cases of malignant lymphoma and 17 cases of benign lymphadenitis. Ultrasonographic findings were reviewed retrospectively. The incidence of following ultrasonographic features was found to be significantly higher in malignant lymphoma than in benign lymphadenitis. These were; (1) longitudinal and transverse diameter ratio(L/T) < 2.0, (2) a delineation of multiple nodes, (3) a tendency of fusion, (4) an irregular margin, (5) hypoechoic masses with heterogeneous internal echoes, (6) a presence of line echoes and (7) an absence of hilum. These 7 ultrasonographic features were used in combination for a scoring system to discriminate malignant lymphoma from benign lymphadenitis. When ultrasonographic findings of lymph nodes fulfilled more than 3 of the 7 features, malignant lymphoma was diagnosed with a sensitivity of 98.0% and a specificity of 76.5%. Ultrasonographic evaluation of swollen cervical lymph nodes using a high-frequency transducer would be informative and should be performed prior to a surgical biopsy.