Importance:Older adults, especially those with frailty, have a higher risk for complications and death after emergency surgery. Acute Care for the Elderly models have been successful in medical wards, but little evidence is available for patients in surgical wards. Objectives:To develop and assess the effect of an Elder-Friendly Approaches to the Surgical Environment (EASE) model in an emergency surgical setting. Design, Setting, and Participants:This prospective, nonrandomized, controlled before-and-after study included patients 65 years or older who presented to the emergency general surgery service of 2 tertiary care hospitals in Alberta, Canada. Transfers from other medical services, patients undergoing elective surgery or with trauma, and nursing home residents were excluded. Of 6795 patients screened, a total of 684 (544 in the nonintervention group and 140 in the intervention group) were included. Data were collected from April 14, 2014, to March 28, 2017, and analyzed from November 16, 2018, through May 30, 2019. Interventions:Integration of a geriatric assessment team, optimization of evidence-based elder-friendly practices, promotion of patient-oriented rehabilitation, and early discharge planning. Main Outcomes and Measures:Proportion of participants experiencing a major complication or death (composite) in the hospital, Comprehensive Complication Index, length of hospital stay, and proportion of participants who required an alternative level of care on discharge. Covariate-adjusted, within-site change scores were computed, and the overall between-site, preintervention-postintervention difference-in-differences (DID) were analyzed. Results:A total of 684 patients were included in the analysis (mean [SD] age, 76.0 [7.6] years; 327 women [47.8%] and 357 men [52.2%]), of whom 139 (20.3%) were frail. At the intervention site, in-hospital major complications or death decreased by 19% (51 of 153 [33.3%] vs 19 of 140 [13.6%]; P < .001; DID P = .06), and mean (SE) Comprehensive Complication Index decreased by 12.2 (2.5) points (P < .001; DID P < .001). Median length of stay decreased by 3 days (10 [interquartile range (IQR), 6-17] days to 7 [IQR, 5-14] days; P = .001; DID P = .61), and fewer patients required an alternative level of care at discharge (61 of 153 [39.9%] vs 29 of 140 [20.7%]; P < .001; DID P = .11). Conclusions and Relevance:To our knowledge, this is the first study to examine clinical outcomes associated with a novel elder-friendly surgical care delivery redesign. The findings suggest the clinical effectiveness of such an approach by reducing major complications or death, decreasing hospital stays, and returning patients to their home residence. Trial Registration:ClinicalTrials.gov Identifier: NCT02233153.