A possibility of detection of BRAF mutation has been studied by means of polymerase chain reaction in punctate from the thyroid node with the aim of diagnostics of high-differentiated cancer on pre-operative stage. A study includes 94 patients with nodal lesions of the thyroid. According to cytological investigation of material, received by fine-needle aspiration biopsy, papillary thyroid cancer was revealed in 47 patients, follicular tumor-in 35 and nodal colloid goiter in 12 patients. In case of papillary thyroid cancer data of genetic analysis showed the following indices of sensitivity, specificity and diagnostic accuracy: 86%, 100% and 92% correspondingly. Detection of BRAF mutation could be used in pre-operative differential diagnostics of high-differentiated cancer and benign nodal lesions of the thyroid.