The neutrophil percentage to albumin ratio (NPAR) has been associated with prognosis of various cardiovascular diseases, but its role in acute type A aortic dissection (AAAD) mortality remains unclear. The aim of this study was to investigate the relationship between preoperative NPAR and in-hospital mortality in AAAD patients. Clinical data from patients who underwent AAAD surgery at the Cardiac Medical Center of Fujian Province between January 2020 and April 2024 were retrospectively analyzed. Patients were categorized into three groups based on NPAR tertiles. Univariate and multivariate logistic regression analyses were employed to identify factors contributing to in-hospital mortality. The predictive performance of NPAR was assessed using ROC curve analysis. The results revealed that out of 813 AAAD patients meeting the inclusion criteria, 137 (16.9%) died in hospital. Multivariate logistic regression analysis indicated that compared to the low tertile group, the odds ratios (95% CI) for in-hospital mortality in the middle and high tertile groups were (OR 3.041, 95% CI: 1.502-6.158, p = 0.002) and (OR 6.586, 95% CI: 3.324-13.049, p<0.001), respectively. Additionally, cardiopulmonary bypass time (OR 1.010, 95% CI: 1.007-1.013, p<0.001) and mechanical ventilation time (OR 1.115, 95% CI: 1.082-1.150, p<0.001) were also independently associated with in-hospital mortality in AAAD patients. The area under the curve for NPAR was 0.708 (95% CI: 0.676-0.739) (p<0.001), with an optimal cut-off value of 24.105, yielding a sensitivity of 73.7% and a specificity of 64.8%. In conclusion, higher preoperative NPAR may be independently associated with increased in-hospital mortality, suggesting its potential as a novel indicator for monitoring AAAD patients.