mmon clinical scenario [1]. The prevalenceof thyroid nodules is ~18-40% in Chineseadults [2]; however, only 5-10 percent of allthyroid nodules are malignant. Although withthe development of the ultrasound technique,several ultrasonographic characteristics havebeen associated with thyroid malignancy[3], individual ultrasound features arenot accurate predictors of thyroid cancer.Thyroid fine-needle aspiration [FNA] hasbeen recommended by various organizationsfor the more precise preoperative diagnosisof thyroid nodules [4]. Non-diagnostic rateof FNA comparison and estimate betweenthe other studiesMaterials and Мethods: We performedover 100 FNA using one pass of the 21-Gneedle attached to a 10 ml syringe withoutlocal anesthesia in 2015. All the FNAswere performed without the guidance ofultrasound. Recent study 100 cases of themwere not selected for a specific method.Results: In total there were 100 patientsrecruited in the study with a mean ageof 45.94±13.13 years and 83.0% femalepatients.The Non-diagnostic rate was comparedbetween groups with different needlesizes and methods. In the 22 G group,non-aspiration showed a decreased NDrate as compared to aspiration [44.21 vs.76.76%, P<0.001;]. In the non-aspirationgroup, a lower ND rate was revealed in the25-G needle group compared to the 22-Gneedle group [34.97 vs. 44.21%, P=0.032;].Notably, the ND rate in the 25 G group wassignificantly lower than in the all 22 G group[34.97 vs. 58.13%, P<0.001;]. In the 21 Ggroups, aspiration showed a decreased NDrate as compared to aspiration [44.21 vs.76.76%, P<0.001;]. 21G aspiration groupshowed decrease twofold ND rate ascompared 22G aspiration group [31.63 vs.76.76%, P<0.001;]Conclusion: There have been studiesusing various needle types [regular needle,needle with a stylet or spinal needle [5]and different needle sizes from [21 G to27 G] with or without aspiration duringthe procedure. Numerous factors influencethe diagnostic rate in thyroid FNA, amongwhich the nodule component is an extremelyimportant factor [6]. In general, the morecystic the percentage of each nodule, thehigher the rate of non-diagnostic, with the lowest ND rate in the solid nodule using a25-G needle at 26.77% and the highest inthe cystic nodule using 22 G aspiration at85.19%. A similar trend was found in eachgroup with lowest rate of ND in the 25 Gnon-aspiration group and highest in the 22G aspiration group.