Objective: Retrospective analysis of routinely collected data using verbal and social autopsy tools to identify the medical causes of death and contribution of non-biological factors towards infant mortality Setting: The study site was Health and Demographic Surveillance System (HDSS), Ballabgarh, North India Participants: All infant deaths during year 2008 to 2012 were included for verbal autopsy whereas infant deaths from July 2012 to December 2012 were included for social autopsy. Outcome measures: Cause of death ascertained by validated verbal autopsy tool and level of delay based on three delay model using INDEPTH social autopsy tool were the main outcome measures. Results: Infant mortality rate during study period was 46.5/100 live births. Neonatal deaths contributed to 54.3% of infant deaths and 39% occurred on first day of life. Birth asphyxia (31.5%) followed by Low Birth Weight (LBW)/prematurity (26.5%) were the most common causes of neonatal death. While infective cause (57.8) was the most common cause of post-neonatal death. Care-seeking was delayed among 50% of neonatal deaths and 41.2% of post-neonatal deaths. Delay at level 1 was most common, observed in 32.4% of neonatal deaths and 29.4% of post-neonatal deaths. Deaths due to LBW/prematurity were mostly followed by delay at level 1. Conclusion: High proportion of preventable infant mortality still exists in an area which is under continuous health and demographic surveillance. There is need to enhance home based preventive care to enable the mother to identify and respond to danger signs. Verbal autopsy and social autopsy could be routinely done to guide policy interventions aimed at reduction of infant mortality.