Vascular calcification can predict cardiovascular (CV) morbidity and mortality in patients with end-stage renal disease. We evaluated the prevalence, association factors, and outcomes of chest X-ray-detected aortic arch calcification (AoAC) in patients undergoing peritoneal dialysis (PD). Methods: We included 190 patients undergoing PD (mean age, 52.6 ± 14.3 years) for whom chest radiographs were available. AoAC revealed by chest X-ray was graded from 0 to 3 according to an AoAC score (AoACS). Multiple regression analyses were used to determine the factors associated with AoACS. After adjusting for age, sex, PD duration, diabetes mellitus, mean blood pressure, and history of CV disease, the association between AoAC grading and mortality were assessed using the Kaplan–Meier curve and Cox proportional hazard model. Results: Age (p < 0.001), PD duration (p = 0.004), history of CV disease (p < 0.001), and renal Kt/V (p = 0.031) were associated with AoACS. After a mean follow-up of 55.1 ± 32.1 months, patients with Grade 2 (p = 0.011) or Grade 3 (p < 0.001) AoAC had higher all-cause mortality than patients with Grade 0 AoAC. In addition, patients with Grades 2 and 3 AoAC had higher CV-related mortality than those with Grades 0 and 1 AoAC (p = 0.013). Grade 2 [hazard ratio (HR) = 2.736; 95% confidence interval (CI), 1.038–7.211; p = 0.042] and Grade 3 AoAC (HR = 3.289; 95% CI, 1.156–9.359; p = 0.026) remained associated with all-cause mortality after adjustment. Similarly, Grades 2 and 3 AoAC (HR = 36.05; 95% CI, 3.494–372; p = 0.026) significantly correlated with CV mortality after adjustment. Conclusion: In patients undergoing PD, CXR-detected severe AoAC was an independent risk factor for all-cause and CV mortalities.