Acute type A aortic dissection (AAD) is a serious life-threatening cardiovascular emergency with high in-hospital mortality without aggressive clinical treatment. The study intended to identify the relationship between platelet (PLT) to platelet distribution width (PDW) ratio (PPR) and in-hospital mortality in postoperative patients with type A AAD. A total of 171 type A AAD patients were recruited in this retrospective study from January 2017 to December 2019. Receiver operating characteristics (ROC) were exploited to determine the best cut-off value of PPR, and then patients were sub-grouped into the low-PPR group and high-PPR group, according to the optimal value of PPR. Finally, univariate, and multivariate analyses were carried out to examine the prognostic value of PPR. The value of PPR was 9.76, and the mortality was statistically higher in the low-PPR group than in the high-PPR group (29.1% vs. 6.0%, P < 0.01). The area under the ROC curve (AUC) of PPR was 0.724 (95% CI, 0.633-0.815; P < 0.001) with a 56.4% sensitivity and 80.6% specificity. Multivariate analysis showed that serum PPR was an independent factor associated with in-hospital mortality (hazard ratio (HR): 1.151; 95% confidence interval (CI): 1.035 -1.297; P = 0.010). Serum PPR can be used as an independent predictor of in-hospital mortality in postoperative patients with type A AAD.