Fever of infant and small child is one of the greatest parental concerns. Mostly the source of fever is viral infection, but sometimes it can be serious bacterial infection: meningitis, sepsis, osteomyelitis, urinary tract infection, pneumonia and enteritis. Non-identified bacterial infection may be a cause of disablement or even death. Infant and younger children up to 36 months of age are in the highest risk period for invasive bacterial infection. After the examination of febrile infant the practitioner has to take a wise decision, especially if febrile infant looks well enough and there is no focus of infection. It is not reasonable to admit all febrile infants and do tests to all of them or start empiric antibiotic therapy. In order to protect infants from no identification of serious bacterial infection it is important for a physician to know the evaluation and management tactics of febrile infants. Thus, the salient question for any physician is: "When can a febrile infant be safely discharged from the emergency room?" Most often proposed recommendations for the management of febrile infants in the literature come predominantly from Boston, Philadelphia and Rochester prospective studies. Criteria introduced in these recommendations demonstrate a safe and effective way of screening febrile infants for a serious bacterial infection. Each management strategy involves criteria such as child's age, temperature, clinical appearance, white blood cell count, urinalysis, cerebrospinal fluid test, stool screening, chest radiography. The purpose of this article is to review the data and to validate optimal recommendation regarding the management of febrile infant and child 3 to 36 months of age.