Hyperbilirubinemia is a common problem during the neonatal period and is the most common reason for readmission after early hospital discharge of the healthy near term and term infants. This early discharge policy along with limited follow-up facilities in developing countries and inadequate communication between physicians and parents necessitates a prognostic test to predict hyperbilirubinemia in these newborns; for early and effective management and prevention of potential complication before it occurred. This observational analytical study was done to determine the predictability of day1 total serum bilirubin (TSB) level as a screening test and identify the best cutoff value which would predict neonates likely to develop significant hyperbilirubinemia. The study was carried out in the Department of Neonatology and Department of Gynecology and Obstetrics, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from 1st April 2013 to 31st March 2014. A TSB level of ≥17mg/dl after 72 hours was defined as significant hyperbilirubinemia. By purposive sampling method, 100 healthy late preterm and term neonates fulfilling the inclusion criteria were enrolled and 89 were finally analyzed. Among 89 neonates 14(15.74%) developed significant hyperbilirubinemia (Group II) and 75(84.26%) did not develop hyperbilirubinemia (Group I). Mean time of sample collection was similar in both groups. Mean TSB level on day1 was significantly higher in Group II (5.97±1.74mg/dl) than Group I (3.19±1.4mg/dl). By using ROC (Receiver Operating Characteristic) analysis, TSB level of 5.65mg/dl on day 1 has the best combination of sensitivity (86%) and specificity (91%) to predict neonates at risk of significant hyperbilirubinemia (AUC-0.880, p=0.001). At this cut-off PPV was 63% and NPV 97%. Total serum bilirubin level on first day of life predicts neonates at risk of subsequent significant hyperbilirubinemia and late preterm and term babies with TSB level of ≥5.65mg/dl on day 1 of life should be followed up strictly either in the hospital or in the outpatient department on day 5.