Coronary atherosclerotic heart disease (CHD) is highly prevalent and deadly globally. Coronary artery bypass grafting (CABG) aims to restore blood flow, alleviate angina, and reduce mortality in CHD patients. Despite its benefits, CABG often leads to complications, particularly pulmonary infections, which significantly impact patient prognosis and impose substantial financial and social burdens. Effective interventions focus on promoting lung function recovery. This study aims to assess the prevalence and risk factors of post-CABG pneumonia in an Egyptian sample to mitigate these risks. Methods: This retrospective study analyzed 137 patients undergoing isolated CABG at Beni-Suef University Hospital from January 2018 to January 2024. Patients were subgrouped based on postoperative pneumonia occurrence. Data analysis included Pearson's Chi-square, t-test, Mann-Whitney U test, and binary logistic regression using SPSS v20, with p<0.05 considered significant. Results: In this study of 137 CABG patients, 10.9% developed pneumonia. Significant risk factors included older age, higher BMI, diabetes, hypertension, lower ejection fraction, longer CPB and operative times, prolonged ventilation, re-intubation, re-opening, extended ICU stays, and increased IABP use. Conclusion: Pneumonia significantly impacts CABG outcomes. Key risk factors include advanced age, obesity, diabetes, low ejection fractions, prolonged surgery and ventilation, reintubation, extended ICU stays, and IABP use.