The word "Demographic Surveillance" means to keep close track of the population dynamics. Vadu HDSS deals with keeping track of health issues and demographic changes in Vadu rural health program (VRHP) area. It is one of the most promising projects of National relevance that aims at establishing an intervention research setting with objectives To create a longitudinal data base Monitoring trends in public health problems Keeping track of population dynamics Evaluation of intervention services The HDSS includes 22 villages from Shirur and Haveli blocks in the VRHP settings and a comparison area covering 18 villages from Khed block. It serves to monitor trends in demographic and health indicators like crude birth rate, crude death rate, migration rate, maternal mortality rate, infant, under five, neonatal, post-neonatal, early neonatal, still birth and perinatal mortality rates; as also indicators of fertility like age specific and Total Fertility Rate. One of the many innovative features of HDSS Vadu is surveillance through network of local people envisaging a sustainable surveillance system. Data base created under HDSS Vadu is used by research studies carried out in HDSS Vadu. Major output we get from such type of surveillance system is the periodic demographic statistics to see the changes in demographic pattern of the area. In addition various research studies are carried out along with regular surveillance such as Verbal Autopsy survey, non-communicable disease risk factor Surveillance, Fertility surveillance which would directly reflect on health related issues of the population.