The objective of this study was to evaluate whether Doppler ultrasound (DUS) is of additional value to gray-scale ultrasound (GSUS) in predicting the benign or malignant nature of thyroid nodules. A total of 1,502 solid thyroid nodules ≥ 10 mm were evaluated. Suspicious vascularity (predominantly or exclusively central blood flow) was observed in only 5% of the nodules. This finding showed 96% specificity, but only 15% sensitivity. GSUS alone showed sensitivity and specificity of 88.7% and 68.2%, respectively, which did not improve with the addition of DUS (sensitivity of 89.4% and specificity of 66.4%). In non-suspicious nodules on GSUS, the type of vascularity on DUS did not modify the risk of malignancy, which was low. In suspicious nodules on GSUS, suspicious vascularity on DUS increased the risk of malignancy, but non-suspicious vascularity did not reduce this risk. DUS provided no additional value to GSUS in predicting the benign or malignant nature of thyroid nodules. Arch Endocrinol Metab. 2015;59(1):79-83