Building on the success of the previous ISBMEs in 2004, 2006, and 2008, the 4th International Symposium on Biomedical Engineering, IEEE ISBME 2009, is developing to become an annual international conference series held in Thailand. IEEE ISBME 2009 covers the broad research areas on biomedical engineering in which all engineers, scientists, physicians, medical doctors and technologists are invited to share the researches and recently developed technologies. IEEE ISBME 2009 will be held during December 14 to 18, 2009 in Bangkok, Thailand. The conference agenda will consist of plenary and keynote lectures, workshops, symposia, as well as the technical tours. The 4-page accepted papers will be included in the IEEE Xplore Database. IEEE ISBME 2009 is organized by the Thai Engineering in Medicine and Biology Society (ThaiEMBS), in conjunction with Mahidol University, the first University in Thailand which has offered the biomedical engineering program for 12 years, since 1998.