Welcome to the proceedings of the 2003 International Symposium on Parallel and Distributed Processing and Applications (ISPA 2003) which was held in Aizu-Wakamatsu City, Japan, July 2–4, 2003. Parallel and distributed processing has become a key technology which will play an important part in determining, or at least shaping, future research and development activities in many academic and industrial branches. This international symposium ISPA 2003 brought together computer scientists and engineers, applied mathematicians and researchers to present, discuss and exchange ideas, results, work in progress and experience of research in the area of parallel and distributed computing for problems in science and engineering applications. There were very many paper submissions from 13 countries and regions, - cluding not only Asia and the Pacific, but also Europe and North America. All submissions were reviewed by at least three program or technical committee members or external reviewers. It was extremely difficult to select the presen- tions for the symposium because there were so many excellent and interesting ones. In order to allocate as many papers as possible and keep the high quality of the conference, wefinally decided to accept 39 papers (30 long papers and 9 short papers) for oral technical presentations. We believe all of these papers and topics will not only provide novel ideas, new results, work in progress and state-of-the-art techniques in this field, but will also stimulate future research activities in the area of parallel and distributed processing with applications.