Neonatal mortality mostly occurs due to avoidable causes which could be prevented if quality health services were available at prenatal, delivery and postnatal periods. In general, these causes are related to biological conditions, socioeconomic disparities and health services accessibility. Hence, even in cities where the economic development is high, it is fundamental to elucidate factors that contribute to the causality of neonatal deaths. The aim of this study was to analyze the factors associated to neonatal deaths in Londrina-PR, from 2000 to 2009. Neonatal deaths were investigated according to characteristics of mothers, newborns and health system city services through an ecological study with a retrospective and descriptive approach. Data were obtained from Birth Certificates, Death Certificates and Infant Death Investigation Forms provided by the Municipal Committee for Prevention of Maternal and Infant Death obtained from the Mortality Information Center assigned under the City Health Department. Regarding maternal characteristics, more than 60.0% were young adults (aged from 12 to 27), mean age of 25.8. Over this ten-year period, the number of teenager mothers decreased from 22.9% to 8.5%. Out of the total, 83.5% were married, 73.9% had 8-11 schooling years and 52.7% did not have a job. Most women (91.4%) received prenatal care and 55.1% of them attended to 1-6 prenatal care appointments. Almost all mothers had some sort of health problems during pregnancy: 82.7% presented with premature labor and 36.7% had renal and urinary conditions. Slightly more than 51,0% led to natural deliveries. Over the years, surgical deliveries increased from 35.4% to 61.5%. As for characteristics of newborns who died, 56.9% were male and 86.0% were caucasian. About 60.0% were born with 22-31 weeks of gestational age and 60.7% weighted under 1500 grams and 73.0% presented with asfixiation at the first minute. Over the studied period, prematurity rates remained elevated. Mean death age was 4.9 days. Most deaths occured at early neonatal period (73.9%) and the Neonatal Mortality Rate decreased from 21.2 to 14.8 between 2000 to 2009. The leading death causes were perinatal conditions (77.6%) followed by congenital anomalies (20.0%). Out of all avoidable deaths, 77.1% occured due to causes that could be prevented if adequate control over pregnancy and labor care were available. As for the city health services attended by the newborns' mothers, 62.3% used the public health system. Almost all labors took place in hospitals (96.5%), and 63.7% of these facilities provided obstetric and neonatal intensive care. In the studied period, the use of hospital facilities with maternity/nursery and neonatal intensive care wards increased from 39.2% to 66.6%. The neonatal death period was statistically associated to premature labor (p<0.01), urinary tract infeccion (p<0.05), arterial hypertension/pre-eclampsia (p<0.01), birth weight (p<0.01), gestational age (p<0.01), Apgar score at 1st and 5th minutes (p<0.01), place of delivery (p<0.01) an...