Purpose: The purpose of this study was to investigate the effects of an intensive teaching program on the knowledge level of MI in patients with a myocardial infarction. Method: The subjects were 47 patients with a myocardial infarction. Of the subjects 23 were assigned to the experimental group and 24 to the control group. The data were collected through a questionnaire (Lee, 1992; Nam, 1998) survey of knowledge level. The data collection was done about MI between September 15, 1999 and December 31, 2000 after hospital discharge. Data were analyzed using the SAS program and the results are as follows. Results: 1. There were no significant difference in knowledge level of the MI (P=0.621) between the two groups before the teaching program was given. 2. After 4 weeks the knowledge level about MI was significantly higher in the experimental group compared to the control group (P = 0.000). 3. After 12 weeks the knowledge level about MI was significantly higher in the experimental group compared to the control group (P= 0.000). 4. After 4 weeks the experimental group was at a higher scores of knowledge category about MI for nature of disease (P=0.000). risk factors, (P=0.000), diet (P=0.000), medication (P=0.000) exercise and daily activities (P=0.000) as compared to the control group. 5. After 12 weeks the experimental group was at a higher scores of knowledge category about MI for nature of disease (P=0.000). risk factors (P=0.001). diet (P=0.000), medication (P=0.000) exercise and daily activities (P=0.000) as compared to the control group. Conclusion: The above findings indicate that the intensive teaching program used for the experimental group in this study was effective in increasing the knowledge level about MI of the patients with a myocardial infarction.