Introduction: Knowledge of gestational specific survival is of paramount importance to ensure the best use of limited resources. However, gestation specific mortality rates are not available for Sri Lanka. Objectives: To determine the gestation specific neonatal mortality rates for extreme premature babies in a Level III neonatal unit in Colombo, Sri Lanka Methods: A retrospective study was conducted at, De Soysa Hospital for Women, Colombo on the neonatal deaths that occurred from 01.01.2024 to 31.12.2025. Permission was obtained from the head of the institution. Babies whose gestations were unknown and those transferred out due to bed unavailability were excluded. Data on births and deaths were recorded from birth registers and cross checked with the perinatal death review statistics and death registers from the neonatal unit. Descriptive analysis was conducted using Microsoft Excel for Mac 2025 v16.103.2. Results: There were 76 extreme preterm live births with 762g mean birth weight(MBW). Nineteen babies(25%) were below the limit of viability(BW500g. All 20-21week babies had BW