Sepsis (also known as bloodstream infection or generalized infection) is a life-threatening condition. Currently, thanks to the widespread use of vaccinations, the occurrence of generalized infections, including those caused by Haemophilus influenzae, is becoming increasingly rare. However, due to the outbreak of armed conflict in Ukraine, the increasing percentage of unvaccinated Ukrainian children, and their migration, an increase in the number of cases with this etiology can be expected. In the following article, a clinical case of a 15-month-old Ukrainian boy with symptoms of respiratory tract infection is presented. The child was vaccinated according to the Ukrainian vaccination schedule, and during the diagnostic process, sepsis caused by Haemophilus influenzae was detected. Early diagnosis and the use of broad-spectrum antibiotic therapy contributed to therapeutic success and the prevention of severe complications associated with sepsis.