Identifying hyperglycaemia during postoperative period is essential for neonates. The objective of the study was to analyse the accuracy and reliability of continuous glucose monitoring (CGM) device for detecting hyperglycaemia during postoperative period in neonates. In this prospective study, hourly glucose recordings by CGM device and six hourly by glucometer glucose (GG-reference test for patient management) were collected in ten surgical neonates during first three postoperative days. Mean absolute relative difference (MARD) and proportion of CGM values within +/- 15%/15mg/dL, +/- 20%/20 mg/dL, and +/- 30%/30 mg/dL of GG, were analysed from matched pair CGM and GG recordings. The diagnostic performance of CGM for neonatal hyperglycaemia (> 150 mg/dL) was expressed as sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV); and the clinical reliability was assessed in Clarke Error Grid Analysis. A total of 720 CGM glucose readings, 120 matched-paired glucosereadings by CGM --GG, and 37 episodes were hyperglycaemia by GG. The MARD was 10.76 %; the per-centages of glucose readings within 15%/15 mg/dL, 20%/20 mg/dL, and 30%/30 mg/dL were 94.6%, 97.3% and 100% during the hyperglycaemia period. The sensitivity, specificity, PPV and NPV to detect hyperglycaaemia by CGM device were 100%, 93.9%, 88% and 100 % respectively. In Clarke Error Grid Analysis, 97.3 % points were in zone A and B during the hyperglycaemia period. Conclusion: CGM device can be a clinically reliable tool for hyperglycaemia management during postoperative period in neonates.