Background <p>Physical performance and nutritional status evaluated in frailty are increasingly recognized as important predictors of postoperative outcomes in older adults patients but remain under-assessed during routine preoperative assessment. This study aimed to evaluate the association between frailty tools and 180-day postoperative mortality in patients aged ≥ 75 years undergoing surgery.</p> Methods <p>We conducted a single-center retrospective cohort study over a five-year period (2020–2024). Patients aged ≥ 75 years who underwent surgery under anesthesia were included. Data were extracted from a structured hospital database, and frailty was assessed using the Mini Nutritional Assessment – Short Form (MNA), the SARC-F questionnaire (SARC-F) and the Short Physical Performance Battery (SPPB). Mortality at 180 days was compared across these three frailty scores. Multivariable logistic regression was performed to estimate the association between frailty scores and 180-day mortality, after adjustment for age, gender, American Society of Anesthesiologists physical status classification system (ASA), surgical time, and surgical urgency.</p> Results <p>Among 11,954 surgical patients aged ≥ 75, frailty scores were available in 250 to 500 patients depending on the tool. Pathological values of MNA, SARC-F, and SPPB were each associated with significantly increased 180-day mortality. After adjustment, MNA (aOR = 3.56, 95% confidence interval (CI) 1.64–7.72, <i>p</i> = 0.001), SARC-F (aOR = 2.03, 95% CI 1.19–3.46, <i>p</i> = 0.009), and SPPB (aOR = 2.63, 95% CI, 1.15–6.05, <i>p</i> = 0.023) remained independently associated with mortality.</p> Conclusion <p>Malnutrition and sarcopenia risk were significantly associated with increased mortality in surgical patients aged ≥ 75, independently of traditional risk scoring like ASA. These findings support the added value of frailty screening tools during preoperative assessment in older surgical patients.</p>