Objetivo: Caracterizar la sobrevida y factores asociados en prematuros de extremo bajo peso al nacer (EBPN). Método: Cohorte de 93 neonatos 30 semanas). Las muertes ocurrieron principalmente en período neonatal (97%), las principales causas fueron: hemorragia pulmonar (21,2%), enfermedad de membrana hialina (18,2%) y prematuridad extrema (18,2%). Se estimó mayor probabilidad de sobrevida a mayor PN y EG, observándose diferencias significativas al comparar los grupos 800-899g vs. 900-999g y Objective: To characterize the survival and its related factors in extremely low birth weight infants (ELBW). Methods: Cohort of 93 premature infants weighing 30 weeks). Deaths occurred mainly in neonatal period (97%), highlighting pulmonary hemorrhage (21.2%), hyaline membrane disease (18.2%) and extreme prematurity (18.2%) as the most important causes of death. Higher survival probability with greater BW and GA was found, detecting significant differences when comparing the groups of 800-899g versus 900-999g and between <25 weeks of gestation and 25-26 weeks. The use of ANC was significantly associated with better survival, but the number of doses administered was not related with the survival. Also, the best Apgar score at the minute and five minutes were associated with better survival. In overall analyses or by categories of BW and GA, gender, surfactant administration, and the condition of small for GA, were not associated with the survival. Conclusions: Nowadays, survival of Chilean ELBW infants begins in 24 weeks improving with greater GA. Consequently, strategies are required to avoid the premature birth or to extend the opportunity of the delivery in cases of maternal-fetal risk