The survival rates and the influential perinatal factors of extremely low birth weight (ELBW) infants were compared between two periods, including January 1997 through May 1998 (Period 1, n = 84) and June 1998 through December 2000 (Period 2, n = 145). The survival rate was 48.8% (41/84) during Period 1 and 55.2% (80/145) during Period 2. Gestational age (GA) and birth weight (BW) were the most important factors that influenced the survival rate. The cut off levels, below which mortality rates increased significantly, were GA < 24 weeks and BW < 700 gm during Period 1 and GA < 24 weeks and BW < 500 gm during Period 2. During Period 1, the smallest survival was a female infant with GA of 23 weeks and BW of 530 gm who had no complication and lived well. During Period 2, the smallest survival was a female infant with GA of 21 weeks and BW of 460 gm who was discharged with home oxygen therapy. She was admitted again via emergency due to sudden onset of apnea and cardiac arrest 4 days after discharge, and she died 4 days after the 2nd admission. Our results did not show any advantages to maternal transfer or delivery by Cesarean section. The early neonatal mortality rate was still high during Period 2 and accounted for 50% of the overall neonatal mortality rate. This implies that further training to improve the neonatal care, especially during the early stage of the first week should be reinforced to reduce neonatal deaths. Prevention of the births of extremely premature infants should be more emphasized to decrease neonatal mortality and morbidity rates. When the delivery of an ELBW infant is impending, an active plan of treatment for all infants of GA > or = 24 weeks or BW > or = 500 gm seems appropriate.