This book contains most of the papers presented at the 4th International C- ference on Extreme Programming and Agile Processes in Software Engineering (XP 2003), held in Genoa, Italy, May 2003. The XP 200n series of conferences were started in 2000 to promote the - change of new ideas, research and applications in the emerging field of agile methodologies for software development. Over the years, the conference has - come the main world forum for all major advances in this important field. Also this year the contributions to Agile Methodologies and Extreme P- gramming were substantial. They demonstrate that the topic is continuing to gain more and more momentum. In spite of some criticism of agile meth- ologies, everyone agrees that they address some unresolved needs of software practitioners. People still do not know how to develop software on time, with the desired features, and within the given budget! This volume is divided into several thematic sections, easing reader’s na- gation through the content. Full papers are presented first, followed by research reports, papers from the Educational Symposium, and papers from the Ph.D. Symposium. The presentations given during three panel sessions held at the conference conclude the book. The section on Managing Agile Processes includes contributions highlighting the sometimes difficult relationship between agile methodologies and mana- ment, and includes approaches and suggestions that should facilitate the acc- tance of agile methodologies at the different levels of management.