This bookis the resultof merging two workshopsseries,namely, oneon comp- erized guidelines and protocols and the other one on knowledge management for healthcareprocedures. Themergeresultedinthe KR4HCworkshop:Knowledge Representationfor HealthCare:Data,Processes,andGuidelines. This workshop was held in conjunction with the 12th Conference on Arti?cial Intelligence in Medicine (AIME 2009), in Verona, Italy. The book included, in addition to the full-length workshop papers, invited peer-reviewed advanced papers on lessons learned in these ?elds. The KR4HC workshop continued a line of successful guideline workshops held in 2000, 2004, 2006, 2007, and 2008. Following the success of the ?rst - ropean Workshop on Computerized Guidelines and Protocols held in Leipzig, Germany, in 2000, the Symposium on Computerized Guidelines and Protocols (CGP 2004) was organized in Prague, Czech Republic in 2004 to identify use cases for guideline-based applications in health care, computerized methods for supportingtheguidelinedevelopmentprocess,andpressingissuesandpromising approachesfordevelopingusableandmaintainablevehiclesforguidelinedelivery. In 2006 an ECAI 2006 workshop at Riva del Garda, Italy, entitled "AI Te- niques in Health Care:Evidence-BasedGuidelinesand Protocols"wasorganized to bring together researchers from di?erent branches of arti?cial intelligence to examine cutting-edge approaches to guideline modeling and development and to consider how di?erent communities can cooperate to address the challenges of computer-based guideline development.