Background/Objectives: Coronary artery bypass surgery (CABG) with multiple arterial grafting (MAG) has shown potential to improve patient survival compared to single arterial bypass grafting. Whether this superiority in survival also exists in diabetics is uncertain. We therefore aimed to compare short and long-term outcomes of MAG in diabetic versus non-diabetic patients. Methods: In this retrospective study, we investigated short- and long-term clinical outcomes of diabetic (n = 256) and non-diabetic (n = 800) patients undergoing CABG with MAG between January 1999 and December 2019 at our institution. Results: Diabetics had a significantly higher EuroScore II (1.37 ± 2.4 vs. 0.88 ± 1.58, p < 0.0001) and underwent significantly less bilateral internal thoracic artery (BITA) grafting (51.95% vs. 67.75%; p < 0.0001) compared to non-diabetics. The incidence of postoperative adverse events, such as pneumonia, stroke, and sepsis, did not differ between the two groups. However, diabetics suffered significantly more often from post-cardiotomy cardiogenic shock, renal failure requiring dialysis, and sternal wound infections over the entire follow-up period. Non-diabetics had a significantly higher median survival time of 19.6 years compared to 14.54 years found in diabetic patients (p < 0.0001). Conclusions: Among patients undergoing MAG, diabetic individuals were found to have a significantly lower overall median survival. This emphasizes the importance of diabetes as a risk factor in choosing individual surgical strategies.