The purpose of this study was to test the utility of the Rochester criteria in determining which febrile neonates are at low risk for serious bacterial infections (SBI). This was a retrospective study over a 5-year period of 134 patients younger than 29 days old with fever without a source evaluated in the emergency department. Results of urinalysis, lumbar puncture, peripheral white blood cell count, and cultures of blood, urine, cerebrospinal fluid, and stool were recorded. Of the 134 neonates, 71 were high-risk, 48 low-risk, and 15 were not classifiable by the available data. Nineteen of the 71 high-risk patients (26.8%) had SBI (2 patients had 2 SBI). Three of the 48 low-risk neonates (6.3%) had SBI (1 patient had 2 SBI). None of the 15 nonclassifiable patients had SBI. Employing the Rochester criteria to the fully cultured neonates who could be risk-stratified, the sensitivity, specificity, positive predictive value, and negative predictive value were 86.4%, 46.4%, 26.8%, and 93.8%, respectively. Although outpatient management of febrile neonates may be feasible, a small percentage of neonates meeting low-risk criteria will have a SBI.