This study evaluated the prognostic value of the aortic calcification index (ACI), an estimate of abdominal aortic calcification by plain abdominal computed tomography (CT), in terms of left ventricular (LV) diastolic dysfunction, mortality, and nonfatal cardiovascular (CV) events in peritoneal dialysis (PD) patients.PD patients who received both abdominal CT and echocardiography were divided into a low-ACI group (n=46) and a high-ACI group (n=46).During follow-up (median, 35.2 months; range, 3.6-111.3), 30 patients (32.6%) died and 10 patients (10.9%) developed nonfatal cardiovascular (CV) events. The 5-year event-free survival rates for mortality and nonfatal CV events were significantly lower in the high-ACI group compared with those in the low-ACI group (35.7% vs. 64.1%, P = 0.01). The ACI was positively correlated with left atrial diameter and ratio of peak early transmitral flow velocity to peak early diastolic mitral annular velocity (E/E' ratio; a marker of left ventricular diastolic function). Using multivariate analyses, the high-ACI group (vs. low-ACI group, HR 5.25, 95% CI 1.77-15.58, P = 0.003) and increased E/E' ratio (HR 1.16, 95% CI 1.03-1.31, P = 0.013) were independent predictors for mortality and CV events. The ACI provided a higher predictive value for adverse outcomes (AUC = 0.755, P = 0.002) than the E/E' ratio (AUC = 0.543, P = 0.61).The ACI was significantly associated with left ventricular diastolic dysfunction and predicted all-cause mortality and nonfatal CV events in PD patients.