Seventy-seven patients with various underlying diseases underwent real-time ultrasonographic study of the neck. The sonography of lymph nodes can be round or ovoid shaped, discrete hypoechoic nodules, or multiple confluent lobulated heterogeneous or homogeneous hypoechoic masses. Venous invasion by a malignant lymph node can also be demonstrated by ultrasonography as a loss of echogenicity in the vessel wall. Twenty-five patients with malignant cervical lymph nodes showed homogeneous discrete hypoechoic nodules. Eleven patients with malignant lymph nodes showed a multiple confluent lobulated hypoechoic picture, among them, 2 patients also had discrete hypoechoic nodules. Eight patients with multiple confluent lymph nodes showed evidence of venous invasion. Among 42 patients with a clinically palpable neck mass, 1 showed venous thrombosis in the internal jugular vein, 2 had abscesses, and 3 had normal musculo-skeletal tissues. Among 35 patients with clinically impalpable cervical lymph nodes, 5 patients had cervical lymphadenopathy. All 41 patients with sonographically detectable lymph nodes underwent aspiration cytology or biopsy, and 36 of these showed malignancy, 4 TB lymphadenitis and 1 nonspecific inflammation. No complication was observed in this series. We conclude that ultrasonography is a valuable tool to evaluate cervical lymphadenopathy and to clarify the histopathological features of the affected lymph nodes with the aid of aspiration cytology.