Acute myeloid leukemia is the most common type of leukemia and accounts for a quarter of all leukemias diagnosed in adulthood. If untreated, the cause of death are usually serious secondary infections and bleeding and as many as 70% of patients over 67 are expected to die within one year of diagnosis. In this regard, accurate assessment of the prognosis of the disease plays a crucial role when treating patients. Prognostic indicators are of great importance in this stratification process and in making clinical decisions about the method, type, duration and intensity of treatment. The current WHO classification along with morphological prognostic indicators also includes cytogenetic, molecular and biological prognostic indicators and clinical presentation of the disease itself. Although the karyotype of patients represents the strongest prognostic parameter in AML, however, 45% of patients show a normal karyotype and accordingly belong to the intermediate prognosis. Therefore great attention is focused on potentially present molecular changes. One of the clinically and prognostically significant molecular changes present in as many as a third of patients with AML are mutations in the FLT3 gene, which are constitutively active in over 90% of leukemic blasts. The most common type of FLT3 gene mutations present in up to 30% of adult patients with de novo diagnosed AML are internal tandem duplications, while mutations within the tyrosine kinase domain are second in frequency and occur in up to 14% of adult patients. The aim of this thesis was to investigate the presence of point mutations in the FLT3 gene by establishing a real-time polymerase chain reaction method in a population of adult patients with a normal karyogram and a negative FLT3-ITD mutation. The established real-time polymerase chain reaction method demonstrated the FLT3-TKD mutation in 4 (8.8%) adult patients diagnosed with AML and normal karyogram. The presence of mutations was confirmed by Sanger sequencing. The real-time polymerase chain reaction method proved to be rapid and effective for routine FLT3-TKD screening and selection of appropriate therapy