Abstract OBJECTIVES No reliable scores are available to predict mortality following surgery for type A acute aortic dissection (TAAAD). Recently, the German Registry of Acute Aortic Dissection Type A (GERAADA) score has been developed. We aim to compare how the GERAADA score performs in predicting operative mortality for TAAAD to the European System for Cardiac Operative Risk Evaluation (EuroSCORE) II. METHODS We calculated the GERAADA score and EuroSCORE II in patients who underwent TAAAD repair at the Bristol Heart Institute. As there are no precise criteria to calculate the GERAADA score, we used 2 methods: a Clinical-GERAADA score, which evaluated malperfusion with clinical and radiological evidence, and a Radiological-GERAADA score, where malperfusion was assessed by computed tomography scan alone. RESULTS 207 consecutive patients had surgery for TAAAD, and the observed 30-day mortality was 15%. The Clinical-GERAADA score showed the strongest discriminative power with an area under the curve (AUC) of 0.80 [95% confidence interval (CI) 0.71–0.89], while the Radiological-GERAADA score had an AUC of 0.77 (95% CI 0.67–0.87). EuroSCORE II showed acceptable discriminative power with an AUC of 0.77 (95% CI 0.67–0.87). CONCLUSIONS Clinical GERAADA score performed better than the other scores and it is specific and easy to use in the context of a TAAAD. Further validation of the new criteria for malperfusion is needed.