We carried out a prospective registry-based cohort study at the emergency department of 363 previously healthy well-appearing infants 3-24 months of age with fever without a source ≥40.5°C based on local protocol. Four were diagnosed with occult bacteremia (1.1%; 95% confidence interval: 0-2.2). Recommendations for nontesting for occult bacteremia screening in these children may have to be reconsidered when fever ≥40.5°C. Larger studies are needed to confirm these results.