Extremely preterm infants are prone to hyperglycemia which is associated with increased mortality and morbidity. Insulin sensitivity is variable in extreme prematurity, and its monitoring, prevention, and treatment are a signifcant challenge in the NICU. Frequent changes in fuid composition and volumes, as well as large growth and adaptational nutrient requirements are limited by difcult vascular access and blood sampling and risk of drug incompatibilities. Insulin treatment requires specifc access and signifcantly increases fuid intake and sampling. Clinicians, therefore, often compromise by reducing glucose intake and accepting higher glycemia. We report a case series of 11 extremely low birth weight (ELBW) preterms, born between 23 5/7 and 27 6/7 weeks of gestation, treated for transient hyper‑ glycemia during the frst 2 weeks of life by continuous subcutaneous insulin infusion (CSII). Insulin concentration was 10 IU/ml, administered via 13 mm Accu-Chek® Tenderlink catheters and a commercial insulin pump (Accu-Chek® Combo, Roche Diabetes Care). Insulin treatment was initiated when glycemia was>252 mg/dL (14 mmol/l) in two consecutive blood glucose determinations, except for one case when glycemia was 234 mg/dL (13 mmol/l), despite a previous decrease in glucose infusion rate. The starting dose for the CSII was between 0.01 and 0.08 IU/kg/h. The average duration of the CSII was 5 days (1–16 days). CSII in extreme preterm neonates with hyperglycemia was clini‑ cally feasible and practical by sparing IV lines and volume and appeared as more rapidly efective than continuous IV administration. No adverse events like hypoglycemia or skin infection were recorded.