A practice guideline for the management of febrile infants and children younger than three years of age sparked controversy when it was published in 1993. Surveys indicate that many office-based physicians do not agree with recommendations for venipuncture and bladder catheterization in nontoxic febrile children, and that many employ watchful waiting rather than empiric antibiotic therapy. Surveys of parents note a preference for less testing and treatment. More aggressive management may be appropriate in febrile infants younger than three months old; however, criteria have been proposed to identify infants older than one month who are at low risk for serious bacterial infection. Because of widespread vaccination against Haemophilus influenzae infection, Streptococcus pneumoniae has become the cause of most cases of bacteremia. The risk of serious bacterial infection is greater in younger children and in those with higher temperatures and white blood cell counts. Controversy persists regarding the age, temperature and white blood cell count values that serve as indications for further evaluation or empiric antibiotic therapy.