Background. Globally, prematurity is the leading cause of neonatal mortality, and hypothermia is one of its contributing factors. The goal of this study was to determine the association between hypothermia and mortality. Methods. A prospective, multi-center, descriptive clinical study was conducted in 5 hospitals in Ethiopia. Axillary temperatures were taken at the time of admission to the newborn intensive care units (NICU) and followed during the NICU stay. Results. A total of 3852 premature neonates (<37 weeks) were admitted to the NICUs from July 2016 to May 2018. Of these infants, 1109 (28.8%) died and 2991 (79.6%) had hypothermia. Hypothermia was associated with perinatal asphyxia (89.5%), RDS (86.2%), and resuscitation at birth (82.7%). Admission temperatures in preterm newborns were inversely associated with mortality and morbidity. Conclusion. Hypothermia at admission is associated with neonatal mortality in premature neonates in Ethiopia. RDS and perinatal asphyxia were the main factors associated with hypothermia. The very high prevalence and association with mortality warrants quality improvement interventions.