Despite advances in treatment, no-reflow, large thrombus burden (LTB), and myocardial blush grade (MBG) are associated with adverse cardiovascular outcomes in ST-elevation myocardial infarction (STEMI) patients undergoing percutaneous coronary intervention (PCI). Aortic arch calcification (AAC) is associated with subclinical atherosclerosis and adverse cardiovascular events. We aimed to examine the relationship between AAC and unfavorable angiographic outcomes such as no-reflow, MBG, and LTB in STEMI patients undergoing PCI. A total of 269 consecutive patients who presented with STEMI and underwent primary PCI were included in the study prospectively. Patients were divided into 3 groups according to AAC degree: grade 0, grade 1, and grade 2/3. The relationship between AAC and the predictors of unfavorable angiographic outcomes, including LTB, no-reflow, and MBG, was specifically examined. LTB, no-reflow, and MBG 0/1 were significantly higher in the grade 2/3 AAC group compared to the grade 0 and grade 1 groups (all p < 0.05). Moreover, grade 2/3 AAC was found to be an independent predictor for LTB, MBG 0/1, and no-reflow (p = 0.002, p = 0.005, p = 0.004, respectively). Patients were then classified according to thrombus burden, MBG, and no-reflow status. Grade 2/3 AAC was significantly higher than grade 0/1 AAC in the LTB, MBG 0/1, and no-reflow groups (all p < 0.05). AAC can be used as a reliable indicator in predicting no-reflow, MBG 0/1, and LTB in STEMI patients undergoing primary PCI.