The aim of this study is to assess the efficacy and accuracy of color flow - Doppler sonography (CFDS) in predicting the malignancy of thyroid nodules.Seventy eight consecutive patients (52 females and 26 males), with 78 thyroid nodules (29 single nodules and 49 in a nodular goiter) have been examined by CFDS, before surgery, evaluating the hypoechogenicity of the nodule, the presence of microcalcifications and the halo sign absent and the vascular pattern, which has been classified as follows: absence of blood flow (type I), perinodular blood flow (type II), intranodular, with or without perinodular blood flow (type III), which is considered the most typical pattern of malignancy. On histology 22 nodules as carcinoma (CA) and 56 as benign nodules (BN).have been diagnosed. The most predictive for malignancy, sonographic pattern, “microcalcifications”, has been found in 13/22 CA and in 4/56 BN (P < 0.0001, specificity 93%, sensitivity 59%); “ hypoechogenicity” in 16/22 CA and in 8/56 BN (P < 0.0001, specificity 86%, sensitivity 73%), “absent halo sign” in 18/22 CA and in 16/56 BN (P < 0.0001, specificity 71%, sensitivity 82%.) have been found. On CFD type III pattern has been detected in 17/22 CA and in 24/56 BN (P < 0.15, specificity 57%, sensitivity 77%); type IIIa pattern (intranodular without perinodular blood flow) has been the most predicitve for malignancy (P < 0.0001, specificity 100%, sensitivity 36%).The combination of type III pattern with “hypoechogenicity” in 13/22 CA and in 2/56 BN (p < 0.0001, specificity 93%, sensitivity 59%) has been found, with “absent halo sign” in 15/22 CA and in 3/56 BN (P < 0.0001, specificity 94.6%, sensitivity 68%), has been foudn, with “microcalcification” in 10/22 CA and in 0/56 BN (P<0.0001, specificity 100%, sensitivity 45%) has been found. The combination of “microcalcifications” and absent halo sign” with type III pattern has been the most specific for malignancy, being detected in 11/22 Ca and 2/56 BN (P < 0.0001, specificity 96%, sensitivity 50%). In conclusion our results suggest that CFDS has an useful role in the assessment of thyroid nodules and it may provide information highly predicitve for malignancy, above all when multiple, sonographic and vascular patterns are contemporaneously present in a thyroid nodule.