Objective To evaluate the interobserver variability in the thyroid imaging reporting and data system (TI-RADS) description of sonographic features of thyroid nodules with different sizes. Methods The retrospective study was conducted on 225 thyroid nodules. All the cases were divided into ≤1.0 cm group and ＞1.0 cm group according to the diameters. Interobserver variability was determined using Cohen's Kappa statistics. Results About the sonographic features of thyroid nodules, the shape, internal content and calcifications exhibited substantial agreement in both groups. There was moderate agreement with regard to echogenicity, posterior

attenuation and vascular pattern in two groups. The kappa values of internal content, echogenicity, calcifications and posterior attenuation were higher in

≤1.0 cm group, while those of shape and vascular pattern were higher in ＞1.0 cm group. Of the elastography, there was also moderate agreement, and in

particularly the kappa values were equal. There was moderate agreement on boundary and echotexture in ≤1.0 cm group, while there was substantial agreement

in ＞1.0 cm group. There was fair agreement on margin in ≤1.0 cm group, and there was substantial agreement in ＞1.0 cm group. Conclusion There are higher

interobserver agreement on the TI-RADS description of sonographic features of thyroid nodules, and there are differences in some description between

different sizes of thyroid nodules.