Therapeutic drug monitoring (TDM) enables individualization in the treatment to optimize clinical benefit and minimize drugs’ side effects. Critically ill septic patients represent a challenge for antimicrobial treatment because of pathophysiological impact of sepsis on pharmacokinetics of drugs. The aim of this study was to assess the appropriateness of gentamicin and amikacin dosing in critically and noncritically ill patients, as well as to estimate the need for its regular therapeutic monitoring.