Newborn babies in need of critical medical attention are normally admitted to the neonatal intensive care unit (NICU). These infants tend to be preterm, have low birth weight, and/or have serious medical conditions. Neonatal survival varies, but progress in perinatal and neonatal care has notably diminished mortality rates. In this selected review, we examine and compare the NICU mortality rates and etiologies of death in different countries. Methods: A literature search was conducted in Ovid MEDLINE, OLDMEDLINE, EMBASE Classic and EMBASE. The primary endpoint was the mortality rates in NICUs. Secondary endpoints included the reasons for death and the correlation between infant age and mortality outcome. For the main analysis, we examined all infants admitted to NICUs. Subgroup analyses included extremely low birth weight infants (based on the authors’ own definition), very low birth weight infants, very preterm infants, preterm infants, preterm infants with a birth weight of ≤1500g, and by developed and developing countries. Results: The literature search yielded 1,865 articles, of which 20 were included. The total mortality rates greatly varied among countries. Infants in developed and developing countries had similar ages at death, ranging from 4 – 20 days and 1 – 28.9 days, respectively. The mortality rates ranged from 4% – 46% in developed countries and 0.2% – 64.4% in developing countries. Conclusion: The mortality rates of neonatal intensive care units vary between nations but remain high in both developing and developed countries.