The objective of this study is to analyze the relationship between the success factors(organizational agreement, task fitness, top management support, user involvement, and linkage between BPR and ERP systems) and the performance(user satisfaction) of ERP systems. The success factors of concern would show positive relationships with the user satisfaction. Data were collected from 57 firms that have installed ERP systems. The responding firms were asked to visit the website of the researcher for the questionnaire survey. The result showed a positive relationship between the organizational agreement and the user satisfaction. This study also found that the user involvement had a negative relationship with the user satisfaction. The findings suggest that the firms adopting ERP systems need to establish the organizational agreement on the ERP system development which would be the critical factor for the successful system. It is also suggested that the user involvement should be controlled for the successful ERP systems.