Thyroid cancer is the main endocrine malignancy. Its incidence is steadily growing and what is alarming is its increase in children and adolescent population. Pediatric thyroid carcinomas differ from the adult ones in phenotype as well as in genetics. These carcinomas tend to be clinically more aggressive, with more frequent local and distant metastases. However, their long-term prognosis is better in comparison with the adult thyroid cancers. Due to the rarity of the disease, there is lack of data on genetic changes in this age group. Knowledge on the genetic background of thyroid cancer in children will help to precise diagnosis and prognosis of the disease and to personalized treatment.Key words: adolescents - carcinoma - gene - genetics - children - mutation - next generation sequencing - thyroid.