Background: Each year, four million newborns die around the world, nearly all of them in developing countries. The fourth millennium developing goal of reducing child mortality cannot therefore be met without substantial reduction in neonatal deaths. Study objective: the study will enlight us on magnitude, determinants and contributing factors of the neonatal death among children admitted at neonatal ward KCMC northern Tanzania Methodology: This was an analytical cross-sectional hospital based study. Data was collected in the neonatal unit at KCMC. All the neonatal deaths occurring within the first months of life were identified and the possible causal factors sought by looking into the file and additional information were sought from mothers. A checklist of important informations was formed and put in the neonatal ward so that all admission during the study period to contain that information in the file. The study was conducted from October 2010 to March 2011. The collected data processed and analyzed using SPSS version 16. Results: we were able to enlore 819 children among them 453(55.3%) were males and 366(44.7%) were females. 62.5% were admitted in the first 24 hours and 73(8.9%) were admitted 8 days after delivery. There 144 neonatal deaths with the death rate of 17.6%.majority of deaths occurred during early neonatal period (79.9%). Males deaths were 82 (18.1%) and females were 62 (16.9%). The commonest causes of deaths were prematurity (52.1%), birth asphyxia (30.6%), sepsis (29.2%) and congenital malformations (9.7%). Neonatal risk factors were low birth weight of 1500g (57%) with a p value of < 0.001, < 7 Apgar score at 5th minute with a p value of < 0.001 and twin children with a p value of < 0.001.While maternal risk factors found were age of < 20 and > 40 years at delivery with p value of 0.02, not attending ANC, complications during labor and employed mothers. Conclusion and Recommendations: prematurity and birth asphyxia remains the main cause of neonatal mortality. Effort to reduce number of preterm deliveries, improving intrapartum care and intensive care for low birth weight babies would lead to a substantial reduction in neonatal mortality.