While most observers agree about the bene.ts of service-oriented computing, there is less of an agreement about suitable architectural and interaction styles for Web Services applications. Of equal importance is the current lack of agreement about basic design principles for making decisions about what should constitute a service and its interface, and related considerations of service granularity. The transition towards service-oriented computing necessitates re-evaluation of design methodologies that are used in the construction of enterprise applications. Web Services design is an active research area and while there is some agreement about the basic design principles there are no comprehensive design methodologies for Web Services at present. There is a need for input from the research community and industry-based practitioners in order to develop design frameworks to support best practices for Web Services projects. The focus of this workshop was on methods, frameworks and approaches for the design of service-oriented applications, and the workshop provided a forum for the discussion of design objectives, methods and guidelines for developing Web Services applications. Workshop discussion included other related topics such as design of industry-domain Web Services, design of Web Services for enterprise application integration, and methods for transforming existing component-based applications for SOA deployment. The aim of the workshop was to bring together researchers and industry experts and provide a forum for exchange of ideas about design of Web Services and related issues. We have received paper submissions with topics including the architecture and design of service-oriented applications, engineering semantic services, designing reusable services, Web Service con.ict management, and service discovery. All submitted papers were reviewed by three reviewers, and ten papers were selected for workshop presentations based on originality, relevance to the workshop topics, and overall quality. We thank the authors for their contribution to the workshop. We thank all of the members of the Program Committee who were instrumental in ensuring the quality of the WDSOA’05 workshop, the organizers of the ICSOC conference and workshops, in particular Mike Papazoglou, Frank Leymann, and Winfried Lamersdorf for their help in planning and organizing the workshop. Special thanks to Christian Zirpins for his assistance with preparing the proceedings and collaboration in organizing the workshop, and Paco Curbera nfor his support in publishing the proceedings.