This paper presents the results of a field survey on perceived upper extremity discomforts among Thai VDT users. Questionnaires were given to 153 VDT users from academic institutions, government agencies, and business organizations to collect information about VDT tasks, VDT workstations, computer accessories layouts, and physical discomforts. Users were divided into three groups according to the dominant input device (keyboard or mouse). Three computer accessories layouts based on the positions of the keyboard, mouse, and monitor were considered in this study. It is found that VDT users who used the mouse as their dominant input device reported high upper extremity discomforts when the mouse is positioned far from the body. From the three accessories layouts considered, the frequent use of the keyboard does not show any apparent impact on the upper extremity discomforts among Thai VDT users.