SUMMARY OBJECTIVE: This study aims to determine the demographic characteristics of cancer patients admitted to an emergency department and determine the relationship between the frequency of admission to the emergency department and oncological emergencies and their effect on mortality. METHODS: This observational, prospective, diagnostic accuracy study was performed in the ED of a tertiary care hospital. Patients over the age of 18 who were previously diagnosed with cancer and admitted to the emergency service for medical reasons were included in the study. We recorded baseline characteristics including age, gender, complaints, oncological diagnosis, metastasis status, cancer treatments received, the number of ED admissions, structural and metabolic oncological emergency diagnoses in the ED, discharge status, length of hospital stay, and mortality status. RESULTS: In our study, 1205 applications related to the oncological diagnosis of 261 patients were examined. 55.6% of the patients were male, and 44.4% were female. The most common metabolic oncological emergency was anemia (19.5%), and the most common structural oncological emergency was bone metastasis-fracture (4.6%.) The mean score of admission of patients to the emergency department was four times (min: 1 max: 29) during the study period. A total of 49.4% (n: 129) of the patients included in the study died during follow-up, and the median time of death was 13 days after the last ED admission. CONCLUSION: The palliation of patient symptoms in infusion centers that will be established in the palliative care center will contribute to the decrease in the frequency of use of emergency services.