BACKGROUND Data on the effectiveness of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) in reducing cardiovascular (CV) risk in patients undergoing peritoneal dialysis (PD) are limited. We investigated the association between ACEI/ARB use and CV outcomes in patients initiating PD. METHODS In this observational cohort study, we identified from the United States Renal Data System all adult patients who initiated PD from 2007 to 2011 and participated in Medicare Part D, a federal prescription drug benefits program, for the first 90 days of dialysis. Patients who filled a prescription for an ACEI or ARB in those 90 days were considered users. We applied Cox regression to an inverse probability of treatment weighted cohort to estimate the hazard ratios (HRs) for the combined outcome of death, ischemic stroke or myocardial infarction (MI) and each outcome individually. RESULTS Among 4879 patients, 2063 (42%) used an ACEI/ARB. Patients were followed up for a median of 1.2 years. We recorded 1771 events, for a composite rate of 25 events per 100 person-years. ACEI/ARB use (versus nonuse) was associated with a reduced risk of the composite outcome {HR 0.84 [95% confidence interval (CI) 0.76-0.93]}, all-cause mortality [HR 0.83 (95% CI 0.75-0.92)] and CV death [HR 0.74 (95% CI 0.63-0.87)], but not MI [HR 0.88 (95% CI 0.69-1.12)] or ischemic stroke [HR 1.06 (95% CI 0.79-1.43)]. Results were similar in as-treated analyses. In a subgroup analysis, we did not find any effect modification by residual renal function. CONCLUSIONS ACEI/ARB use is common in patients initiating PD and is associated with a lower risk of fatal CV outcomes.