Abstract.Inter‐organizational systems, which represent the majority of competitive information systems, have received increasing attention from researchers. This study focuses on the implementation of customer‐based inter‐organizational systems (CIOS). A model is constructed and tested, based on literature in IS implementation and organizational innovation. Data from 73 organizations who have implemented such systems are gathered through a questionnaire. Two classes of independent variables, innovation factors and support factors, are examined for their influence on CIOS implementation success. While no innovation factors emerge as important, support factors, such as customer training and top management support, are found to significantly facilitate successful implementation of such systems. Implications for research and practice are disc