PurposeNo study has compared 30-day and 90-day adverse postoperative outcomes between old-age patients with and those without sarcopenia.Patients and methodsWe categorize elderly patients receiving major surgery into two groups according to the presence or absence of preoperative sarcopenia that were matched at a 1:4 ratio through propensity score matching (PSM). We analyzed 30-day or 90-day adverse postoperative outcomes and mortality in patients with and without sarcopenia receiving major surgery.ResultsMultivariate logistic regression analyses revealed that the patients with preoperative sarcopenia were at significantly higher risk of 30-day postoperative mortality (adjusted odds ratio [aOR]. = 1.25; 95% confidence interval [CI]. = 1.03–1.52) and 30-day major complications such as postoperative pneumonia (aOR = 1.15; 95% CI = 1.00-1.40), postoperative bleeding (aOR = 2.18; 95% CI = 1.04–4.57), septicemia (aOR = 1.31; 95% CI = 1.03–1.66), and overall complications (aOR = 1.13; 95% CI = 1.00-1.46). In addition, surgical patients with sarcopenia were at significantly higher risk of 90-day postoperative mortality (aOR = 1.50; 95% CI = 1.29–1.74) and 90-day major complications such as pneumonia (aOR = 1.27; 95% CI = 1.10–1.47), postoperative bleeding (aOR = 1.90; 95% CI = 1.04–3.48), septicemia (aOR = 1.52; 95% CI = 1.28–1.82), and overall complications (aOR = 1.24; 95% CI = 1.08–1.42).ConclusionsSarcopenia is an independent risk factor for 30-day and 90-day adverse postoperative outcomes such as pneumonia, postoperative bleeding, and septicemia and increases 30-day and 90-day postoperative mortality among patients receiving major surgery.Condensed abstractNo study has compared 30-day and 90-day adverse postoperative outcomes between patients with and those without sarcopenia. We conducted a propensity score?matched (PSM) population-based cohort study to investigate the adverse postoperative outcomes and mortality in patients undergoing major elective surgery with preoperative sarcopenia versus those without preoperative sarcopenia. We demonstrated that sarcopenia is an independent risk factor for 30-day and 90-day adverse postoperative outcomes, such as postoperative pneumonia, bleeding, septicemia, and mortality after major surgery. Therefore, surgeons and anesthesiologists should attempt to correct preoperative sarcopenia, swallowing function, and respiratory muscle training before elective surgery to reduce postoperative complications that contribute to the decrease in surgical mortality.