Background: Fine needle aspiration biopsy (FNAB) is a useful tool in the diagnosis of thyroid nodules. However, some limitations exist as approximately 25% of the cases cannot be distinguished with this method. Therefore, identification of novel diagnostic markers is very important in improving the papillary thyroid carcinoma (PTC) diagnosis. microRNAs (miRNAs) are small regulatory RNA molecules that have been involved in a variety of biological processes, including tumorigenesis. Moreover, determination of miRNAs with prognostic, diagnostic, and therapeutic potential is of a great interest today. Aims: In the present study, we evaluated the expression level of miR-30a-5p in serum and FNAB samples of PTC patients. Methods: A total of 60 cases were included in the study, with the patients subdivided into four groups; benign, atypical cells of undetermined significance (ACUS), malignant group, including Hurthle cell PTC (HC-PTC), and malignant without Hurthle cell PTC (non-HC-PTC). Peripheral blood and FNAB samples of the cases were collected. The serum and FNAB expression levels of miR-30a-5p among the groups were compared. The miR-30a-5p expression level was determined using real-time polymerase chain reaction (RT-PCR). Results: According to both pre- and postoperative pathological diagnosis, miR-30a-5p levels were significantly increased in both serum and FNAB samples of HC-PTC and non-HC-PTC groups compared to other groups. This increase was more evident in the non-HC-PTC group (p=0.0245 for FNAB, p=0.0166 for serum). Conclusions: The results of this study suggest that miR-30a-5p might be a novel diagnostic marker candidate in PTC. Further studies are required to investigate this possibility.