The adjustment of the minimum inhibitory concentrations for anti-tuberculosis drugs used in classical cultivation methods and the obtaining of more accurate data on the level of drug resistance, makes it possible to evaluate cases with different results to phenotypic and genotypic methods of anti-tuberculosis resistance testing. The evaluation of different types of genotypic resistance, with the description of mutations that confer low or high resistance, is consistent with the level of phenotypic resistance, and also makes it possible to adjust treatment regimens, which ultimately will positively influence the duration and results of treatment. Whenever testing of M. tuberculosis resistance by molecular methods allows, the results should be reported with the specific mutations detected and the description of the clinical implications of this mutation.