According to statistical data thyroid cancer is the most common malignant disease of the endocryne system. The most common occurrence is in the female population. Of the total number of thyroid carcinomas, the most common manifestations are well – differentiated carcinomas, which include papillary and follicular carcinoma. Modern therapy for well-differentiated thyroid cancer consists of primary surgical treatment, postoperative radioiodine therapy and TSH suppressive hormone therapy. External radiation, chemotherapy and other forms of treatment are applied in patients with advanced metastases. A team of health professionals is involved in the treatment. Nurses are equal members of the team who actively and directly participate in thinking and acting during the perioperative period with psychologists and medical specialists: endocrinologists, nuclear medicine physicians, radiologists, specialists of otorhinolaryngology and head and neck surgery, oncologists and anesthesiologists. Perioperative work of a nurse includes preoperative patient preparation, intraoperative and postoperative health care. Nurses are key members of the team and participate in its work within the framework of the competences acquired by their education. The first part of the thesis provides information from the field of basic sciences and clinical medical knowledge of the thyroid gland. Perioperative care of patients is presented below. In accordance with set objectives and hypotheses, the data obtained from the BiS system of KBC Zagreb is analyzed and presented through graphs and tables along with written interpretation. Subjects are patients with a well-differentiated thyroid tumor diagnosis that were surgically treated from 2011 to 2018 at the ORL Clinic. The total sample encompassed 766 patients. From nursing diagnosis in patients diagnosed with well – differentiated thyroid carcinomas, the most often indicated is high risk – high risk for infection.