Background: The primary threat of angina is the higher probability of being exposed to cardiacarrest if not detected and diagnosed in time. If any type of angina is left ignored and untreated, it can lead to myocardial infarction at any stage thereafter. Aim: The aim of the study was to evaluate the effect of intervention guidelines on nursing performance regarding angina patients. Research design: A quasi-experimental design was used to achieve the aim of the study. Setting: The study was conducted in Cardiac Care Unit at Zagazig University Hospitals, Egypt. Sample: A convenient sample of 30 nurses working at CCU was recruited.Tools of data collection: Two tools were used: A structured interview questionnaire, and an observational checklist. The intervention guidelines implemented from June 2017 to May 2018.Results: There was a lack in nurses’ knowledge about angina before intervention guidelines, with mean±SD of 1.1±0.30, which increased in postintervention and follow-up phases of intervention guidelines, with mean±SD of 1.96±0.18, with a statistically significant difference (P=0.000). Moreover, there was a lack in nurses’ practice before intervention guidelines, with mean±SD of 1.13±0.35, which increased in postintervention and follow-up phases of intervention guidelines, with mean±SD of 2.00±0.00 and 2.00±0.00, respectively, with a statistically significance difference (P=0.000). Conclusion: Based on the results of the study, mean scores of nurses’ knowledge and practice were higher in postintervention and follow-up phases of nursing intervention guidelines. Recommendation: Nurses should be trained firstly before they are allotted to working in CCU mainly to understanding how to deal with angina cases.