Urinary tract infections (UTIs) contribute to a significant portion of bacterial infections in neonates and young infants. Criteria for the diagnosis, treatment, and imaging are more established in the 2-to 24-month-old age group. It may not be ideal to apply recommendations from the group older than 2 months to younger patients, because the presentation, risk factors, complications, management, and imaging may not be appropriate for this more vulnerable population. This review provides a summary of the available literature for diagnosis, treatment, and follow-up of a UTI in the neonate or young infant. We review data on imaging to assess for underlying congenital anomalies of the urinary tract. We also provide insight on the use of antibiotic prophylaxis, particularly when vesicoureteral reflux is identified.