We analyzed prenatal history of 277 live low birth weight infants (less than 2,500 g). We tried to determine some perinatal factors that may be associated with good prognosis in this group of babies. The variables analyzed were: maternal age, number of prenatal visits, complication of pregnancy, mode of delivery, birth weight, sex, gestational age. Apgar score at 1 minute and the neonatal morbidity. The population was divided in 3 groups: 1. Less than 1,000 g, (3).2. 1,000-1,499 g, (37) and 3. 1,500-2,499 g (237). Each group was also divided in appropriate for gestational age (AGA) and small for gestational age (SGA). We found that morbidity and the risk of death, is less in the SGA compared with AGA, associated with better prenatal care, higher birth weight and gestational age.