Purpose: The purpose of this study was to determine the differences in the level of disease related knowledge, compliance of health behavior, and educational needs in relation to time (at discharge and 6 months after discharge) among patients underwent percutaneous coronary intervention (PCI). Methods: Data were collected from January 1, 2006 to September 30, 2006 and a total of 60 patients participated in the study. The survey was conducted in patients underwent PCI at the time of discharge right after discharge education was provided and at a follow up visit which was 6 months after discharge. Results: The level of disease related knowledge (p<.001), the compliance of health behavior (p<.001), educational need (p=.496), the sub-item of sexual life (p<.001), follow up (p<.001), diet (p=.021), stress (p<.001) in compliance of health behavior, and the sub-item of specific character of disease in educational needs (p=.015) were significantly different between discharge and 6 months after discharge. Conclusion: The results of this study suggested that further education should be provided to the patients underwent PCI regarding medication, smoking cessation, daily life and exercise at a time of 6 months after discharge in order to increase patient compliance of health behavior.