The purpose of this study is to analyze the mediating effect of informatization level between characteristics of introducing information system and organizational performance in hospital settings, and to provide suggestions to improve the performance level of strategic information system of hospitals. In order to achieve study purpose, a causal path model was developed and empirically tested. Data were collected from 746 managers of 92 hospitals keeping information system in Busan, Ulsan and Kyungnam Province using self-administered structured questionnaire. Major results of this study were as follows; The results of the path analysis showed that organizational characteristics variables except informatization strength within health industry had significant effects on informatization level, and had indirect effects on organizational performance mediated by informatization level. On the other hand, informatization level, especially revelation capability among informatization level variables, was found to have significant direct effect on organizational performance. These results of empirical test imply that informatization level variables are both important affecting factors on organizational performance and mediating factors between organizational characteristics and organizational performance. Therefore, in order to increase organizational performance, measures improving informatization level should be developed and carried out continuously. And, especially, focusing on building and strengthening revelation capability is crucial to those efforts.