Cervical lymphadenopathy is a relatively common finding in pediatric age group and is caused by a wide spectrum of diseases from transient infections to malignancies especially lymphomas. The present study was aimed at evaluating the diagnostic performance of grey-scale ultrasonography, color Doppler ultrasonography and power Doppler ultrasonography in differentiation of reactively and metastatically enlarged cervical lymph nodes in pediatric age group. Fifty children with cervical lymphadenopathies were assessed by ultrasonographic methods. In each patient, the longest (L) and transverse (T) diameters, L/T ratio and presence or absence of the normal hilar pattern were checked by grey-scale ultrasonography. Spectral parameters (resistive and pulsatility indices) and vascular distribution pattern of nodes were recorded by color and power Doppler ultrasonography, respectively. Following the ultrasonographic evaluations, biopsy and/or clinical follow up was applied for six months, based on the clinical and paraclinical findings. Statistical analyses were performed by chi-square test, independent t-test and receiver operator characteristic curves. The mean age of patients was 12.42 +/- 2.42 years. Twenty eight patients (56%) had malignant enlargement of lymph nodes. The mean value of L/T ratio in malignant group was 1.70 +/- 0.22 and 2.40 +/- 0.38 in non-malignant nodes (p < 0.001). Sensitivity, specificity and accuracy of combined grey-scale and power Doppler ultrasonography were 70, 86 and 81%, respectively. Combination of grey-scale and power Doppler ultrasonography is recommended for the differentiation between the malignant and benign lymphadenopathies in children. Moreover, our findings revealed no diagnostic role of color Doppler ultrasonography in the selection of malignant cervical lymph nodes in children.