This paper argues the risks of the humanization programs in hospitals which allow visits by pets. The issue of hospital-acquired infections and the risks posed by the introduction of parasites, including viruses, bacteria and helminths, is here discussed. We highlight the difficulties inherent to the implementation of guidelines to prevent infections in the nosocomial environmentKEY WORDS: Hospitals; infections; humanization; pets.This paper argues the risks of the humanization programs in hospitals which allow visits by pets. The issue of hospital-acquired infections and the risks posed by the introduction of parasites, including viruses, bacteria and helminths, is here discussed. We highlight the difficulties inherent to the implementation of guidelines to prevent infections in the nosocomial environmentKEY WORDS: Hospitals; infections; humanization; pets.