A retrospective cohort study investigated the association between having surgery and risk of mortality for up to 5 years and if this association was modified by incident ESRD during the follow-up period. Summary of Background Data: Mortality risk in individuals with pre-dialysis CKD is high and few effective treatment options are available. Whether bariatric surgery can improve survival in people with CKD is unclear. Patients with class II and III obesity and pre-dialysis CKD stages 3-5 who underwent bariatric surgery between January 1, 2006 and September 30, 2015 (n = 802) were matched to patients who did not have surgery (n = 4933). Mortality was obtained from state death records and ESRD was identified through state-based or healthcare system-based registries. Cox regression models were used to investigate the association between bariatric surgery and risk of mortality and if this was moderated by incident ESRD during the follow-up period. Patients were primarily women (79%), non-Hispanic White (72%), under 65 years old (64%), who had a body mass index > 40kg/m 2 (59%), diabetes (67%), and hypertension (89%). After adjusting for incident ESRD, bariatric surgery was associated with a 79% lower 5-year risk of mortality compared to matched controls (hazard ratio = 0.21; 95% confidence interval: 0.14-0.32; P < 0.001). Incident ESRD did not moderate the observed association between surgery and mortality (hazard ratio = 1.59; 95% confidence interval: 0.31-8.23; P =0.58). Bariatric surgery is associated with a reduction in mortality in pre-dialysis patients regardless of developing ESRD. These findings are significant because patients with CKD are at relatively high risk for death with few efficacious interventions available to improve survival.