In recent years, the number of widespread malignant tumors of the thyroid gland with invasion or compression of the upper respiratory tract, most often with medium to low histological differentiation, has been increasing rapidly, which worsens the prognosis for the recovery of patients. The most important prognostic factors in the case of widespread malignant tumors of the thyroid gland are histological differentiation and the extent of tumor invasion. The urgency of the issue of comprehensive treatment of patients with locally disseminated malignant thyroid tumors is due to the lack of a single tactic, the choice of the scope of surgical interventions and resections of the upper respiratory tract is not defined.
 Objective — to determine medical and surgical tactics for improving the complex treatment of patients with locally disseminated malignant thyroid tumors with invasion and compression of the upper respiratory tract (URT), depending on the degree of spread and histological structure of the tumor.
 Materials and methods. In total, 2,300 patients with malignant tumors of the thyroid gland have been treated. The experimental group included 165 patients (7.2%) with T4a‑b category locally disseminated malignant thyroid tumors. The clinical and morphological characteristics of the patients in the general and experimental groups were analyzed and compared. The patients of experimental group demonstrated lower morphological differentiation of tumors, significantly higher number of regional and distant metastases, older patients’ age, that worsened the prognosis for recovery, and prevalence of men over women.
 Results. Most often, the tumor was disseminated in the URT, 55 patients had signs of URT stenosis of the I—III degree. Urgent tracheotomy was performed in 9 patients with pronounced stenosis of the III degree, which turned out to be very difficult, and 3 patients died during the operation or in the early postoperative period. In the case of initially inoperable T4b tumors, we performed neoadjuvant antitumor chemotherapy, the resulting tumor regression allowed for radical surgery in most patients. Various resections of the latter with the application of a tracheostomy or primary anastomosis were performed in patients with invasion of the upper respiratory tract. The effectiveness of various methods was analyzed depending on the prevalence of invasion and morphological differentiation of the tumor. In the experimental group of radically operated patients, the mortality rate was 31.0%, the recurrence rate was 39.3%.
 Conclusions. The prognosis for recovery in the group of locally disseminated malignant thyroid tumors is worse due to the lower morphological differentiation of tumors, older age of patients, and a greater number of regional and distant metastases. In case of URT stenosis, it is advisable to prepare the patient for radical surgery with intraoperative placement of a tracheostomy. In the case of an initially inoperable tumor, it is advisable to carry out neoadjuvant polychemotherapy. Surgical treatment of locally disseminated malignant thyroid tumors should be as radical, «aggressive» as possible, and the choice of the method of resection of the upper respiratory tract depends on the prevalence of invasion and the degree of differentiation of the tumor, and must comply with oncological principles.