The Centre for Tropical Disease Research Medical School at the University of Guerrero, Mexico has been developing the Sentinel Survey process since 1985. Community-based Sentinel Surveys are a tool for developing dialogue among families, local leaders, district health services and regional and national level health planners about health risks (00). They are based on the premise that through careful, inexpensive measurement, dialogue and using the perspective of the family health possibilities can be changed (02). The video focuses on a village survey (one of 43 sentinel sites in Guerrero) which investigated family practices that might increase the risk of parasites and diarrhoea (10). All households in the village were surveyed by local health workers. Blood, faeces and saliva tests were processed quickly and the data fed back to the community (14). A preliminary risk analysis of common practices such as using contaminated water to wash vegetables or keeping pigs in the yard was also carried out by health staff in the field using laptop computers (15). The results were distributed to the community the next day and demonstrated to the community that by changing certain practices their families' health could be improved (15.30). The information gathered can be shared with other district health authorities, as well as with regional and national level bodies. It can also be used as the basis for dialogue with relevant sectors such as the water or education authorities (23).