The contributions of this publication follow mainly five main topics: Medical Imaging on the Grid; Ethical, Legal and Privacy Issues on HealthGrids; Bioinformatics on the Grid; Knowledge Discovery on HealthGrids and Medical Assessment and HealthGrid Applications. The maturity of the discipline of HealthGrids is clearly reflected on these subjects. There are more contributions related to two main application areas (Medical Imaging and Bioinformatics), confirming the analysis of the HealthGrid White Paper published last year, which outlined them as the two more promising areas for HealthGrids. Along with these two areas, the assessment on the results of HealthGrid applications, also focused by several contributions, denotes also the maturity of HealthGrids. Finally the other two areas (Knowledge Discovery and Ethical, Legal and Privacy Issues) focus on basic technologies which are very relevant for HealthGrids.IOS Press is an international science, technical and medical publisher of high-quality books for academics, scientists, and professionals in all fields. Some of the areas we publish in: -Biomedicine -Oncology -Artificial intelligence -Databases and information systems -Maritime engineering -Nanotechnology -Geoengineering -All aspects of physics -E-governance -E-commerce -The knowledge economy -Urban studies -Arms control -Understanding and responding to terrorism -Medical informatics -Computer Sciences