Objectives: Rationale & Objective: We aimed to investigate the association between abdominal aortic calcification score (AACS) assessed by plain radiograph of lateral abdomen and the risk of cardiovascular (CV) events in patients with pre-dialysis chronic kidney disease (CKD). Methods: Study design: Prospective observational cohort study. Setting & Participants: A total of 2,090 pre-dialysis CKD patients from the Korean Cohort Study for Outcome in Patients With Chronic Kidney Disease (KNOW-CKD) Predictors: Baseline AACS categorized into 0, 1 – 2, 3 – 4, 5 – 6, and ≥ 7. Outcome: The primary outcome of was the composite CV events, defined as a composite of non-fatal CV events and all-cause death. The secondary outcomes were fatal and non-fatal CV events and all-cause death. Analytic Approach: Cox proportional hazard regression. Results: The risk of composite CV events was significantly higher in the subjects with AACS ≥ 7 (adjusted hazard ratio (HR) 1.888, 95% confidence interval (CI) 1.219 to 2.923), compared to that of the subjects with AACS 0. The risks of fatal and non-fatal CV events (adjusted HR 1.052, 95% CI 1.030 to 1.073) and all-cause death (adjusted HR 1.949, 95% CI 1.073 to 3.539) were significantly higher in the subjects with AACS ≥ 7, compared to those of the subjects with AACS 0. Subgroup analyses revealed that the associations were not modified by various clinical contexts, such as age, sex, body mass index, estimated glomerular filtration rate, and albuminuria. Conclusions: AACS assessed by plain radiograph is independently associated with adverse CV outcomes in patients with pre-dialysis CKD. A simple radiographic examination of lateral abdomen may help CV risk stratification in this population.