Aim: Although hyperkalemia is a common encountered electrolyte disorder in the emergency room, there is little information in the literature regarding its clinical results. In this study, the short-term prognoses of patients who applied to the emergency department for any reason and were found to have hyperkalemia were investigated. Materials and Methods: This retrospective cohort study was carried out in a tertiary care university hospital emergency department by using the data provided by a hospital information management system (HIMS) in a year period. The 1st week and 28th day survivals of the patients who applied to the emergency department for any reason and were found to have hyperpotassemia (K >5.11 mg/dL) were evaluated. The relationship between potassium values at the first admission of patients with hyperkalemia and hospitalization or intensive care admissions, age, gender, hemodialysis needs, chronic kidney disease (CKD) and acute kidney injury (AKI), and survival were investigated. Results: In the study, the results of 18,582 serum potassium samples were evaluated. Among the 2,715 hyperkalemia samples, 532 (19.5%) false potassium elevations and 363 (9%) repeat patients were measured. These samples were excluded from evaluation. Information of seven patients could not be reached and they were excluded from the study. Hyperpotassemia results of 1934 patients were included in the final analysis. It was found that 130 (6.7%) of the patients died within seven days, and 245 (12.7%) died within 28 days. In the study, 7-day and 28- day day mortality of patients who developed AKI, needed hemodialysis, who were hospitalized or located in intensive care unit were found to be significantly higher (p<0.001 for each). There was no statistical difference at 7th and 28th days between patients with CKD and those without CKD. It was found that AKI for patients, hyperpotassemia was associated with hospitalization, death and hemodialysis. Conclusion: Patients with hyperkalemia accompanying AKI carry a risk in terms of mortality and other adverse prognoses. This risk has been found to be weaker in CKD. Hyperkalemia creates a serious risk even in hyperpotassemia close to normal value