With the continuing progress of obstetrical and neonatal care, the limit of human viability has continued to shift towards younger gestational ages. The survival rate as well as the survival without disability increases with each additional week of gestation but, for infants born from 22 to 25 w GA, it is still really low, and the threshold of human viability appears to be limited to the physiological development of the lungs, which take place around the 23rd-24th w GA. At present, the care of such infants, born at the threshold of human viability, presents a variety of complex medical, social, and economical decisions assuming the characteristics of ethical decisions in that the limits between benefits and disadvantages is not so clearcut. What is the true infant's best interest is far to be understood and concern about the ethical basis of providing such intensive care is arising in the scientific community. In this paper the authors provide a review of the ethical basis of decisions related to the care of such infants: to treat, not to treat, intensive or compassionate care, withhold or withdraw treatment.