Thyroid cancers are among the most common endocrine cancers. An inflammation is associated with many stages of cancer. Therefore, in this study, we aimed to evaluate whether it has a prognostic significance inflammation marker. Neutrophil/lymphocyte ratio, platelet/lymphocyte ratio, monocyte/lymphocyte ratio, systemic inflammation response, systemic immune-inflammation index, and neutrophils to lymphocytes and platelets ratio (N/LP) in patients diagnosed with thyroid cancer in the internal medicine outpatient clinic and operated between March 1, 2017 and May 1, 2022 were evaluated retrospectively. Three hundred forty patients were diagnosed with thyroid cancer; 275 (80.9%) of them were women and the mean age was 44.6 ± 13.5 years. Multifocality (P = .02) was significant in patients with invasion. High N/LP ratio (odds ratio: 1.4, 95% confidence interval: 1.0–2.0, p: 0.003) and high invasion (odds ratio: 0.2, 95% confidence interval: 0.1–0.4, P < .01) was found to be significant in patients with tumor size ≥2 cm. There is a relationship between multifocality and invasion, and the risk of invasion increases as the tumor size increases in thyroid cancer. The N/LP ratio was significant as it could be a new marker in showing the relationship between thyroid cancer and its prognosis. Further studies are needed in which the prognosis is followed up, longer-term, more comprehensive, and confounding factors are excluded.