Extremely low birth weight infants (ELBW) are defined by birth weight of less than 1000 g and are frequently born at 27 weeks’ gestation (GW) or younger. The neonatologists’ efforts focused on improvement of intact survival rate, especially for those born at the frontiers of viability at 22/23 GW. Survival rates of >80% for the advanced gestations and > 50% for 23–24 GW have been reported. Higher gestational age and birth weight, female gender, better maternal education, and white race have been recognized as significant predictors of decreased morbidity in ELBW infants. Although the mortality rate has significantly contracted for this group with improved technology and better understanding of pathophysiology, the proportion of surviving infants without sequelae, has not improved as noticeably. We review the short and long-term morbidities in ELBW infants and compare own and literature data. We analyze some of the specific immediate problems for this group such as: respiratory problems, infection, thermoregulation, impaired glucose homeostasis and disturbed cardiovascular and excretory functions as well as late morbidities such as bronchopulmonary dysplasia, late-onset infections, central nervous system occurrences, retinopathy and anemia of prematurity. We also deal with preventive and therapeutic strategies for improved outcome in this sensitive group of patients.