Background. One of the major challenges of modern medicine is prevention and early detection of diseases, especially malignant tumors, since the stage does influence the prognosis and treatment costs. Thyroid involvement is currently one of the leading endocrine disorders in terms of overall morbidity and prevalence in the world. Thyroid cancer is one of the localizations, which being timely detected and properly treated, has a favorable prognosis, when 20–30-year survival rate exceeds 90 %. Therefore, the search for simple, minimally invasive, but highly informative techniques for optimizing the algorithms for diagnosis, differential diagnosis and monitoring of this disease remains a priority. Purpose – to determine and substantiate the diagnostic value of comprehensive assessment of the thyroid status and full blood count values in patients with thyroid nodules. Materials and methods. The study involved 60 patients with thyroid nodules, which according to ultrasonography (US) of the thyroid were classified as TR-4 category of thyroid nodules, TIRADS scale (4–6 points, suspected malignant thyroid changes). The examination included the following: questionnaire, ultrasound examination with fine-needle aspiration puncture biopsy, cytological examination, counting the thyroid hormone concentration, full blood count. The study was carried out at the premises of State Institution “Dnipropetrovsk Medical Academy of the Ministry of Health of Ukraine”. Results. Assessment of thyroid status of patients with thyroid nodules showed a significant correlation between the severity of thyroid malignancy and TSH levels (according to Kruskal – Wallis test, H = 7.30, p < 0.05), FT4 (H = 17.64, p < 0.001) and FT3 (H = 12.41, p < 0.01). Patients of Group I with benign thyroid process showed significant (p < 0.05) decrease in total hemoglobin along with significantly frequent (p < 0.05) microcytic anemia. According to the studies, Group II had a significant (p < 0.05) decrease in total platelet count and plateletcrit, as well as an increased average platelet volume and the percentage of large platelets compared to Group I. The blood values in malignant thyroid process (Group III) are characterized by increased levels of leukocytes and the proportion of eosinophils and basophils in the leukocyte formula compared to Group II (p < 0.05). Conclusions. The outcomes of comprehensive assessment of thyroid status and full blood count values in patients with thyroid nodules can be used in preoperative diagnosis as a differential prognostic tool to assess their malignant potential.