Objectives: In the present study, we investigated the effects of Vitamin D (vit D) deficiency on aggressiveness of papillary thyroid cancer (PTC). Methods: Patients with PTC confirmed with pathological examination, whom were operated by a single surgeon between 2012 and 2017, were included in the study. The data of the patients were analyzed retrospectively. Cancers other than PTC, patients with hyperthyroidism and/or using antithyroid drugs were excluded from the study. The patients were classified as four quartiles according to serum Vit D levels; category 1 (<7.1 ng/mL), category 2 (7.2–11.8 ng/mL), category 3 (11.9–23.4 ng/mL) and category 4 (>23.5 ng/mL). Results: A total of 133 patients (103 female, 30 male) with mean age of 46.4±13.6 (17–82) years were included in the study. There was no significant difference between the categories in terms of preoperative Vit D values according to the evaluated tumor ag- gressiveness characteristics. It was determined that the presence of tumor with a size above 1 cm and T3/4 tumor were not affected by Vit D level. There was no significant difference between Vit D categories regarding the characteristics of aggressiveness such as multicentricity, lymphovascular invasion, central, and lateral metastases. Conclusion: According to our results, serum Vit D levels are not associated with the aggressive tumor characteristics of PTC.