Since the announcement of ISO 9000 standards in 1987, many countries throughout the world have converted these standards into their own national quality standards. The European Community have even imposed ISO 9000 standards on most of the importing goods. As Taiwan's economy depends mainly on its exports, the manufacturing companies in Taiwan must obtain ISO certification in order to compete in the global market. Currently, most reported ISO studies have focused on the issues regarding its implementation profiles, benefits, process model, and difficulties. Very few studies have looked into the issues of information system (IS) structure for ISO 9000 implementation. Through a field survey, this study identifies the factors influencing the success in ISO certification, validates an ISO 9000 information system model, analyzes and categorizes the information items required by the ISO certification process, and analyzes the current IS profile in the ISO-certified manufacturing companies. The IS model proposed by this study consists of eight major information systems: strategic management, design management, purchase management, production management, marketing management, quality management, document management, and human resources/finance management. It was found that purchase management, production management, and marketing management are the three most popular information systems being computerized, followed by human resources/finance management, document management, and quality management. The critical success factors of ISO 9000 certification are: information profile, corporate culture and policy. communications between organizational units, motives of certification, education and training, and top-manager commitment. Among the eight information systems, inventory management, purchase management, warehouse management, supplier management, bill-of-material management, quality management, material requirement planning, document management, quality auditing, and manufacturing resource planning subsystems are most helpful in obtaining and maintaining IS 9000 certification. With respect to the level of IS applications, transaction process systems (TPS) such as inventory system, payroll system, accounting system, purchase system, human resources system are most widely used, followed by management information systems (MIS) such as production planning/control system, production schedule system, material requirement planning system, and quality auditing system. The decision support system/executive information systems are used in a few companies. The machinery industry has a higher degree of computerization than the other industries. In general, an ISO 9001 certified company has a higher degree of computerization than an ISO 9002 certified company. There are no significant differences in the degree of computerization based on the company size and the size of exporting market.