Neonatal diabetes mellitus (NDM) is a monogenic form of diabetes occurring mainly in the first 6 months of life. Approximately 30% of transient NDM (TNDM) cases will have an activating mutation in the K ATP channel genes ABCC8 and KCNJ11. The majority of the patients with KCNJ11 mutations who are receiving insulin treatment can be transferred to treatment with sulfonylurea (SU), with an improvement in metabolic control and quality of life. Intermittent continuous glucose monitoring (iCGM) is used to assess the current and retrospective interstitial glucose, providing information such as hypo/hyperglycemia tendency and time on target. This case report describes the use of iCGM in the transition from insulin treatment to glibenclamide in a patient with TNDM caused by a pathogenic variant of KCNJ11. This is the first report of a successful outpatient transition from insulin to glibenclamide, in a Brazilian child with TNDM using iCGM (FreeStyle Libre@). The remote monitoring and online management allowed the patient to safely stay at home during the transition from insulin to SU, especially important in the context of the COVID-19 pandemic. We conclude that iCGM is a helpful tool in cases of NDM and should be used to increase safety and speed up dose adjustments in outpatient transition from insulin to glibenclamide.