Sarcopenia has emerged as a comprehensive predictor of mortality in diseased populations. The aim of this study was to evaluate the prognostic and predictive value of psoas muscle thickness/height (PMTH) measurement in patients with acute type A aortic dissection (AAAD). A retrospective analysis of patients (from January 2020 to December 2020) who underwent AAAD surgery at our institution was conducted. PMTH, as a measure of sarcopenia, was measured by preoperative computed tomography. Patients were classified into two groups according to the cut-off value of PMTH. To balance potential bias, a 1:1 propensity score matching (PSM) with a caliper 0.05 was conducted. PSM analysis created 68 pairs of patients. In short-term outcomes, a lower PMTH value was strongly correlated with higher in-hospital mortality and renal failure. Receiver operating characteristic (ROC) analysis suggested that sarcopenia had good predictive capabilities in in-hospital mortality, with the area under curve (AUC) of 0.81 [95% confidence interval (CI): 0.64-0.97]. During a median follow-up of 37 months, 24 (19.4%) patients died, including 16 in low PMTH group and 8 in high PMTH group. Kaplan-Meier analysis indicated the sarcopenia significantly affected long-term survival [log-rank P=0.02; hazard ratio (HR) 2.53 (95% CI: 1.13-5.66)]. Multivariable Cox regression analysis revealed that sarcopenia was an independent predictor for decreased survival [HR 2.73 (95% CI: 1.15-8.78)]. Sarcopenia defined from the PMTH may be a useful tool for predicting short- and long-term mortality in patients after AAAD surgery.