Numerous studies show that vital signs can act as predictors of death. We test these hypotheses with data from the summer of 2022, when Spanish emergency departments (EDs) were overwhelmed. The main objective of this study is to describe the clinical factors of patients who died in the emergency department. This study is a retrospective descriptive analysis of patients who attended an ED between January 2021 and September 2022, focusing on those who died during the same episode. Clinical, sociodemographic and management variables were evaluated. A comparison between the study years was performed. A bivariate analysis was conducted to examine the relationship between the cause of death, triage level, and survival. During the study period, 116,870 patients attended the ED, 317 (0.27%) of whom died during the same ED episode. Of the patients who died, 54.3% were men and 45.7% were women. 182 people died in 2021 and 135 in 2022. The primary cause of death is respiratory. The profile of a patient who dies in the emergency department is an elderly male (>80 years old) coming from their home with a triage level indicating a risk to life (urgent or emergent), presenting cardiovascular risk factors, and dying from a respiratory cause. Factors such as hypotension, tachypnea, hypoxia, elevated creatinine, and lactate levels, observed during the first minutes in the emergency department, significantly determine patient survival (p < 0.05). It can be asserted that clinical parameters can estimate patients’ immediate vital prognosis in the first hours of attending the emergency department, especially among elderly patients and those with a severe triage level (emergent/urgent). Creating a score for elderly patients with certain clinical parameters upon triage could help to provide better healthcare and reduce the delay in attending to them.