Decision analysis was used to evaluate the probable health benefits, complications, and costs of six management strategies for febrile children at risk for occult bacteremia. The strategy that combined blood culture with empiric oral antibiotic treatment for all patients was predicted to prevent the highest number of major infections and to have the lowest cost per major infection prevented. The strategy that combined a leukocyte count and blood culture for all patients, followed by empiric antibiotic treatment for those with leukocyte count greater than or equal to 10,000/mm3, had almost equal cost and clinical effectiveness and avoided many antibiotic complications. Culture of blood specimens from all patients and no empiric treatment constituted the third most clinically effective intervention but was the least cost-effective in this model. Giving a 2-day oral course of amoxicillin without testing had the lowest average cost per febrile patient but was the least clinically effective intervention. However, the low degree of effectiveness of empiric treatment alone was based on the assumption that oral amoxicillin therapy was only 20% effective in preventing major infections after bacteremia. At higher estimates of effectiveness, treatment alone became a more viable strategy. We conclude that approaches which combine blood culture with empiric antibiotic treatment are the most clinically effective and the most cost-effective strategies for children at risk for occult bacteremia.