The measurement of illness severity and mortality risk isessential to making fair comparisons of outcomes among hospitalsand routinely available markers of risk such as birth weight,gestational age, and sex do not adequately capture the dimension ofillness severity. Scoring systems are a means to quantify clinicalstates that are difficult to summarize by other subjective orobjective means. The desirable properties of neonatal scores are notmuch different in essence from those required for scores used inpaediatric population. This properties have been described asincluding: (1) ease of use; (2) applicability early in the course ofhospitalization; (3) ability to predict mortality, specific morbidities;and (4) usefulness for all groups of neonates to be described.So SNAP-II and SNAPPE-II developed as a simple neonatalillness severity and mortality risk scores.