Assessment of neck lymph nodes is essential in patients with head and neck cancers for predicting the patient's prognosis and selecting the appropriate treatment. Ultrasonography is a useful imaging tool in the assessment of neck lymph nodes. Greyscale ultrasonography assesses the size, distribution, and internal architecture of lymph nodes. Doppler ultrasonography evaluates the intranodal vascular pattern and resistance of lymph nodes. Contrast-enhanced ultrasonography provides information on lymph node parenchymal perfusion. Elastography allows qualitative and quantitative assessment of lymph node stiffness. This article reviews the value of greyscale, Doppler and contrast-enhanced ultrasonography as well as elastography in the assessment of malignant nodes in the neck.