Acute coronary syndrome and pulmonary embolism (PE) are clinical entities sharing similar presentation and risk factors. Risk scores and indexes help to identify disease severity in both diseases. In this study, we aimed to evaluate if the Global Registry of Acute Coronary Events (GRACE) risk score could predict 30-day mortality and the need for thrombolytic treatment in patients with acute PE. Patients hospitalized with a diagnosis of PE in our tertiary center between January 2018 and May 2022 were included in this retrospective study. Pulmonary Embolism Severity Index (PESI) and GRACE risk scores on admission were calculated using clinical, electrocardiographic, and laboratory parameters for each patient. A total of 197 patients were included. The 30-day mortality rate was 28.4% whereas 32.5% of the patients required thrombolytic treatment. GRACE and PESI scores were found independent risk factors associated with 30-day mortality and the need for thrombolytic treatment. A cut-off value of 160.5 for GRACE score was associated with 88.5% sensitivity and 89.4% specificity in prediction of 30-day mortality. In contrast, GRACE score had 61.0% sensitivity and 60.0% specificity in the prediction of the need for thrombolytic treatment when the cut-off value was 147. In conclusion, GRACE risk score has an effective discriminating power in determining the early mortality of patients with acute PE. The incidence of short-term PE-related mortality was significantly increased in patients with high GRACE risk scores. Concomitant use of GRACE and PESI risk scores may aid in defining patients with high-risk PE and help predict poor prognosis with high specificity and probability.