Antibiotic stewardship aims to ensure that clinicians administer the right antibiotics, to the right patients, for the right reasons. These principles are being widely applied in medical care, but have been particularly challenging in the NICU. Infectious risk factors and clinical instability are common among neonatal patients, and lead to significant cumulative antibiotic exposures in the NICU setting. Both the frequency with which antibiotics are administered and the potential unintended consequences of antibiotic administration differ between preterm and term infants. Multiple metrics are available to measure antibiotic use, yet no single measure is universally applied to neonatal stewardship.