The 13th Conference on Current Trends in Computational Chemistry (CCTCC) was held on November 12&13, 2004 at the Jackson Hilton Hotel in Jackson, Mississippi. It was attended by almost 200 participants from 30 different countries. The meeting was sponsored by the National Science Foundation (NSF), the National Institutes of Health (NIH), the Army High Performance Computing Research Center, the U. S. Army Engineer Research and Development Center, and the Parallel Quantum Solutions. The conference opened with a presentation by Ronald Mason, JSU President and Deborah Dent, Deputy Director, U. S. Army Engineer Research and Development Center. After these greetings, the focus of the meeting shifted to scientific issues. The plenary lectures were divided into six sessions. The first session included only one talk—the Pulay's lecture given by Peter Pulay from the University of Arkansas. In total, 13 plenary lectures were presented during the 13th CCTCC. The list of speakers includes: M. S. de Vries, University of California at Santa Barbara; A. Toro-Labbe; Pontificia Universidad Catolica de Chile; S. B. Trickey, University of Florida; L. G. M. Pettersson, Stockholm University; R. Jaffe, NASA Ames Research Center; R. Lavery, Institut de Biologie Phisico-Chimique; G. A. Voth, University of Utah; H. Nakatsuji, Kyoto University; G. Chalasinski, University of Warsaw; T. Clark, Friedrich-Alexander University Erlangen-Nurnberg; P. L. Popelier, University of Manchester; and U. Rothlisberger, Federal Institute of Technology, Lausanne. In addition to the plenary talks, the conference program includes three poster sessions. During these sessions, about 150 posters were presented. The 13th CCTCC features two special talks. The first talk was presented Friday night in the Noble Lecture Series by William Lester, Jr. from University of California, Berkeley. The banquet lecture on Saturday night was presented by Joseph Bordogna, Deputy Director, National Science Foundation. The plenary talks and poster presentations were devoted to the current status of computational chemistry. New developments in methodology were discussed. Many talks and posters present applications of computational methods in chemistry, biology, nanotechnology, and material science. High-performance aspects of ab initio methods were also discussed covered by the oral and poster presentations. Abstracts, extended abstracts, and presentations for the conference can be viewed at: http://ccmsi.us/cctcc%5Farchive/. Also, the pictures from the CCTCC are available at the same WebPage. The articles published in this volume highlight the wide variety of the contributions to the conference. We express our sincere gratitude to all the authors for their contributions.