Abstract Background Impaired activities of daily living (ADL) have been identified as an independent risk factor for cardiovascular diseases. This study aims to describe the clinical characteristics, treatment modalities, and prognosis of acute non-ST-segment elevation myocardial infarction (NSTEMI) patients with impaired ADL. Methods The data for this study were derived from a Health and Medical Big Data Superplatform, comprising a retrospective cohort of patients admitted to and discharged from 72 secondary and tertiary hospitals from 2010 to 2023. The inclusion criteria encompassed patients with a discharge diagnosis of NSTEMI.ADL prior to NSTEMI was evaluated using the Barthel index(BI),a widely used assessment tool for evaluating ADL.The patients' BI were obtained from patients’ resident health records, and patients were categorized into two groups: ADL normal and ADL impaired group. A comparative analysis was conducted between the two groups regarding clinical characteristics, treatment regimens, and prognosis. Results The study included 28,227 NSTEMI patients with normal ADL and 1,576 NSTEMI patients with impaired ADL. Baseline data revealed that the ADL impaired group had a higher proportion of females (49.4% vs. 43.2%, p < 0.001), older age (77.0 [69.0, 83.0] vs. 71.0 [66.0, 78.0], p < 0.001), and a higher proportion of patients with KILLIP III and above (25.86% vs. 17.44%, p < 0.001). Additionally, the ADL impaired group had a greater number of pre-existing comorbidities. Regarding treatment, the proportion of patients undergoing percutaneous coronary intervention (PCI) was significantly lower in the ADL impaired group (16.5% vs. 65.3%, p < 0.001). Moreover, the ADL impaired group showed lower utilization rates of antiplatelet agents, ACEI/ARBs, beta-blockers, ARNI, statins, and nitrates, while the utilization rates of diuretics and cardiac glycosides were higher. In terms of prognosis, the ADL impaired group exhibited a higher in-hospital mortality rate (6.03% vs. 3.35%, p < 0.001). During a median follow-up period of 876 days, the ADL impaired group had significantly higher rates of all-cause mortality (61.2% vs. 35.9%, p < 0.001) and cardiovascular mortality (41.8% vs. 24.8%, p < 0.001), while the rate of revascularization (6.69% vs. 9.20%, p = 0.008) was lower. There were no significant differences in the risks of recurrent non-fatal myocardial infarction (10.7% vs. 10.8%, p = 0.935), recurrent stroke (10.90% vs. 9.48%, p = 0.08), and hemorrhagic stroke (0.82% vs. 0.74%, p = 0.806). Following adjustment for age, gender, KILLIP classification, medical history, and treatment strategies in a multivariable Cox regression analysis, impaired ADL remained an independent risk factor for increased all-cause mortality (aHR 1.167, 95%CI: 1.091-1.249, p < 0.001). Conclusions The decline in ADL is significantly associated with adverse clinical outcomes among NSTEMI patients.Baseline characteristics of patientsMedications of patients