['End-stage renal disease (ESRD) is associated with poor medical outcomes. This study aimed to compare early outcomes of elective and emergency operation for diverticulitis among older adults with and without a diagnosis of ESRD.', 'Patients 65 years of age and older with a primary diagnosis of diverticulitis who underwent operative intervention were identified in the 100% Medicare Provider Analysis and Review (MEDPAR) inpatient file from 2004 to 2007. Outcomes between the ESRD and non-ESRD patients (elective and emergent) undergoing operation for diverticulitis were compared. A subgroup analysis in patients only undergoing elective or emergent operation was performed. Multivariable analyses were conducted. In addition, a propensity-matched analysis was applied comparing early outcomes between ESRD patients and well-matched controls consisting of non-ESRD patients.', 'A total of 53,560 patients were identified, with 996 (1.86%) ESRD patients. After propensity matching, 962 ESRD and well-matched non-ESRD patients were identified. In the matched cohort, ESRD patients had greater rates of in-hospital mortality (30.9% vs 7.9%, P < .001), shock/sepsis, pulmonary compromise, wound infection, and acute myocardial infarction. An ostomy was placed more frequently in the ESRD patients (71.3% vs 58.7%, P < .001). Duration of stay and hospital charges also were greater in the ESRD group (18 vs 11 days, P < .001; $137,998.3 vs $67,502.2, P < .001). Similar results were seen when outcomes between matched elective ESRD and elective non-ESRD patients were compared. There was no difference on in-hospital mortality on subgroup analyses between elective versus emergent surgery in the ESRD population (25.4% vs 31.1%, P = .133). On multivariable analysis, ESRD patients had greater odds of in-hospital mortality, and most individual complications when compared with the non-ESRD patients. In addition, the odds of in-hospital mortality and morbidity were greater in the elective ESRD group when compared with elective non-ESRD group and also in the emergent ESRD group when compared with the emergent non-ESRD group.'] Is surgery for diverticulitis associated with high risk of in-hospital mortality and morbidity in older patients with end-stage renal disease?