Nosocomial, hospital-acquired or health care-associated infections occur worldwide, affecting both developed and developing countries. This results in a prolonged hospital stay, increased antimicrobial resistance, increased mortality rate, and significant financial burden on the health care system. Routine preventive measures have led to the decrease in infection spreading; however, it cannot successfully prevent all of them, making a place for the development of new strategies, including probiotics. The aim of this review was to summarize available evidence of the role of probiotics in the prevention of nosocomial infections in children. Currently there is enough evidence showing that Lactobacillus rhamnosus GG administrated in a dose of at least 10 colony-forming units per day during the hospital stay can significantly reduce a risk for nosocomial diarrhea at regular pediatric ward. For other indications including the risk of respiratory tract infections at regular pediatric ward or risk of nosocomial infections at intensive care units we do not have enough evidence to give a recommendation. Therefore, additional research is needed to increase our knowledge and possibly further improve clinical practice.