the objective of this study was to characterize the morbi-mortality of newborns at the neonatal intensive care unit of a teaching hospital located in southern brazil, and verify the association between the following variables: prenatal care attendance, complications at birth, and newborns' length of stay at the unit. this is a retrospective, quantitative study. data collection was performed using the medical records of inpatients of a neonatal intensive care unit, in the year 2006. the data were subjected to statistical analysis. the mortality rate of the studied population was 14.16%. the main causes of death were cardiorespiratory arrest and prematurity. hospital admissions occurred mainly because of respiratory complications and low birthweight. in conclusion, although most mothers attended prenatal care, no statistical significance was found when this variable was crossed with birth complications. length of stay at the unit, on the other hand, showed statistical significance when associated with prenatal care attendance.