The evaluation of EDI controls is important in ensuring the high performance of an EDI system. Although penetration level is strongly associated with performance, the benefits derived arise from the usage level of EDI controls. This suggests that EDI contrls affect the relationship between EDI implementation and performance. Research hypotheses have been empirically tested using responses from Korean companies that have adopted EDI. It has been shown that the integration and utilization of EDI affects its performance.When EDI is highly integrated, formal, informal, and automated controls must be enhanced in order to provide high performance. High utilization affects performance only when automated controls are completely implemented. Empirical analysis confirms that EDI controls affect the relationship between EDI implementation and performance.