CHOIS, the Child Health and Obesity Informatics System This has been developed with the financial support and sponsorships of Illinois Department of Human Services (DHS), The University of Illinois at Urbana-Champaign (UIUC), the National Center for Supercomputing Applications (NCSA), and the National University Community Research Institute (NUCRI). Part of this development was presented at PRAGMA 18 . , is developed using open source portal technology with three-tiered Open Grid Services Architecture, an accepted standard for accessing Grid Computing and other services under Open Grid Collaborating Environments (OGCE). Its web application provides web based forms with 112 different fields to enter data ranging from demographic, height & weight for BMI, to genomic information. Automatic computation of BMI, BMI percentile and the risk of obesity alert are embedded into this system. After successful testing of the prototype, CHOIS is now ready to be used by the Illinois Department of Human Services (DHS) for obesity surveillance. This HIPAA & FERPA compliant secure system, integrating large databases in a high performance grid computing environment, enables school-nurse to collect data on school children and report statistical and surveillance information on BMI to identify those at-risk and obese for obesity prevention and intervention programs.