This study was conducted to assess factors associated with the degree of performance of qualify improvement(QI) activities. A mailed questionnaire survey was conducted between September 15 and October 30, 2000, with the staffs being charge of QI at each of the hospitals with 400 beds or greater. Of the 108 hospitals eligible for inclusion in our study, 79 participated, yielding a response rate of 73.1%. After excluding 12 hospitals that did not perform any QI activities, 117 responses from 67 hospitals were used for the analysis. Using the Malcolm Baldrige National Quality Award Criteria(MBNQAC), perceived performance of QI was measured in terms of the improvement of the quality of clinical practice, clinical supporting department, administrative procedure of receiving care, customer satisfaction, efficiency and standardization of work process. Factors evaluated for the association were the extent of QI implementation, compliance to 5 QI principles, participation of hospital CEOs, budget allocation, history of QI, and bed size. Path analysis was performed to assess the relationship between QI performance and these factors. Major findings of this study are as follows. Hospitals showing higher degree of QI implementation (path coefficient=0.5967, p<0.001)) and better compliance with the basic principes of QI(0.5736, p<0.05) tended to achieve better performance. Path analysis results showed that interest and participation of hospital CEOs(0.1954, p<0.05) and compliance with the basic principes of QI(0.4028, p<0.0001) indirectly affected the outcomes of QI by influencing the intermediate variable of the level of QI implementation. This study results suggest that having employees have a good orientation of the basic concept and principes of QI through relevant training be the most important requirement to achieve better outcomes from QI activities. In addition, to educate leaders of hospitals the need of active implementation of QI is important to encourage their participation and draw strong support for QI programs.