Drug-resistant epilepsy poses a challenge in neonatal patients, especially those in the neonatal intensive care unit (NICU), who have various secondary comorbidities. We present results of four children with a history of drug-resistant epilepsy for whom a ketogenic diet was initiated and used in the NICU. A nonfasting induction into ketosis over 1–2 weeks was utilized, with gradual increases in the ketogenic ratio every 2–3 days. Data were collected retrospectively from a database, which included medical history, daily progress notes, relevant laboratory data, and imaging and diagnostic information. The ketogenic diet was well tolerated in all cases. The most common side effects observed were constipation, hypoglycemia, and weight loss. Serum β-hydroxybutyrate levels demonstrated improved reliability as a marker of ketosis when compared to urine ketones in this population. Perceived benefits to the infants included improved seizure control, increased alertness, and decreased need for invasive respiratory support. These cases demonstrate that the use of the ketogenic diet for treatment of neonatal encephalopathy and refractory epilepsy can be undertaken safely in the NICU and is well tolerated by carefully screened neonates and infants.