The number of individuals diagnosed with myocardial infarction continues to increase; they are usually commenced on several long-term medications post-MI, Patient education regarding these medications is essential. Nurses play a vital role in educating MI patients, and as such, they themselves should be knowledgeable about what they teach. This study aimed to plan, implement, and evaluate the effect of a teaching program about post MI medications on nurses' knowledge. Subjects & methods: An exploratory study was conducted to meet the aim of this study. This study was carried out in CCU in Minia University Hospital and in EL Amiry hospital. The sample included all nurses (33) in the two hospitals. Data were collected through using a questionnaire sheet included two parts: - Part I; included items related to sociodemographic characteristics, Part II; compromised 49 questions covering knowledge related to post myocardial infarction medications (aspirin, beta-blockers, an ACE inhibitors, and statins). Results of this study illustrated that The majority of nurses in both hospitals were females, work as bed side nurses & have no previous training, also the study results revealed that in pretest (before conducting the teaching program) the majority of nurses of both hospitals (University hospital& El Amery hospital) had unsatisfactory level of knowledge about post MI medications while in post test nearly all of them had satisfactory & good knowledge level regarding theses medications (with high statistical significance difference (P.value = 0.000), total knowledge scores of nurses who were working in University hospital were significantly higher score than those who working at El Amery hospital (P.01) . also a significant relation was found between nurses' knowledge and their educational level. Conclusion of this study illustrated that the implementing of the teaching program about post MI medications (beta blockers, aspirin, ACE inhibitors and statins) was successful in improving and upgrading nurses' knowledge about these medications. Hospitals should recommend conducting a teaching program about post MI medications to MI patients.