Background: Early diagnosis of major trauma and rapid transmission of patients to appropriate therapeutic centers have always been issues of concern. Several prognostic models for rapid clinical decision-making and estimating the mortality rate of multipletrauma patients have been presented previously. Objectives: The current study aimed to evaluate the GCS, Age, and systolic blood pressure (GAP) and mechanism, GCS, age, and systolic blood pressure (MGAP) scores of patients with multiple trauma and determine the cut-off points of these scores for predicting mortality rates. Patients and Methods: This cross-sectional descriptive study was included 374 patients with multiple trauma. Data regarding age, mechanism of injury, systolic blood pressure, and Glasgow coma score were collected. GAP and MGAP scores were calculated, and their relationship with the need for surgery, mortality in the ED, and mortality in the hospital ward were investigated. Results: Mean±SD of the MGAP and GAP scores of patients were 24.36±5.04 and 20.53±5.08, respectively. For no need for surgery, survival in the ED, and survival in the hospital ward, areas under the Roc curves for MGAP were 0.75, 0.93, and 0.99, respectively, and for GAP, were 0.74, 0.80, and 0.99. Conclusions: MGAP and GAP scores were used to accurately predict outcomes for patients with multiple traumas. We recommend these simple triage tools for use by emergency medical technicians in pre-hospital settings to refer patients to appropriate trauma centers.