This study was undertaken to evaluate the accuracy of the power Doppler sonographic features in differentiating cervical lymphadenopathy in different diseases. We reviewed power Doppler sonograms of 270 patients with palpable neck nodes (metastases n = 101, lymphoma n = 21, tuberculosis n = 76, reactive n = 72). Confirmed diagnosis was either made by fine-needle aspiration cytology on the largest node or by excision biopsy. In each patient, the largest node was included in the study. The node was evaluated using the vascular pattern, displacement of vascularity and vascular resistance (resistance index, RI, and pulsatility index, PI). Individual groups were compared and the optimum vascular feature in the differential diagnosis was determined. Vascular pattern was more useful in differentiating reactive nodes from malignant nodes, with a sensitivity of 88% for metastases and 67% for lymphoma, and a specificity of 100%. RI with a cut-off value of 0.8 was more accurate in distinguishing metastases (RI > 0.8) from lymphoma (RI 1.5), with an accuracy of 77% in both diseases. When appropriate criteria are used, power Doppler sonography is a valuable adjunct in the sonographic evaluation of cervical lymphadenopathy. ; School of Optometry