Objective. To evaluate the effectiveness of intraoperative visualization and risk factors of central lymph node metastases in unilateral PTC without preoperative clinical signs of central lymph node metastases. Material and methods. There were 227 patients with preoperatively verified thyroid cancer in one lobe without lymph node metastases between January 2018 and December 2018. They underwent hemithyroidectomy and prophylactic central lymphadenectomy (CLE). Results. The follow-up period was 47.6±10.6 months. Metastases were detected in 57 (25.1%) patients during intraoperative visualization and in 72 (31.7%) patients after morphological analysis. Sensitivity and specificity of intraoperative visualization were 76.4% and 98.7%, respectively. Extrathyroidal invasion was significantly associated with higher risk of central lymph node metastases (p=0.006, p<0.001; and p<0.001, respectively). Oncological outcomes did not differ significantly between true- and false-negative results of intraoperative visualization. Conclusion. Intraoperative imaging is valuable to obtain accurate information about status of disease and extent of surgery. Further long-term studies are needed to evaluate clinical benefits of intraoperative visualization. © E.V. RYABCHENKO.