BACKGROUND: Fluid and electrolyte balance is a key concept to understand for maintaining homeostasis, and for a successful treatment of many metabolic disorders. There are various regulating mechanisms for the equilibrium of electrolytes in organisms. Disorders of these mechanisms result in electrolyte imbalances that may be life-threatening clinical conditions. In this study we defined the electrolyte imbalance characteristics of patients admitted to our emergency department. METHODS: This study was conducted in the Emergency Department (ED) of Uludag University Faculty of Medicine, and included 996 patients over 18 years of age. All patients had electrolyte imbalance, with various etiologies other than traumatic origin. Demographic and clinical parameters were collected after obtaining informed consent from the patients. The ethical committee of the university approved this study. RESULTS: The mean age of the patients was 59.28±16.79, and 55% of the patients were male. The common symptoms of the patients were dyspnea (14.7%), fever (13.7%), and systemic deterioration (11.9%); but the most and least frequent electrolyte imbalances were hyponatremia and hypermagnesemia, respectively. Most frequent findings in physical examination were confusion (14%), edema (10%) and rales (9%); and most frequent pathological findings in ECG were tachycardia in 24%, and atrial fibrillation in 7% of the patients. Most frequent comorbidity was malignancy (39%). Most frequent diagnoses in the patients were sepsis (11%), pneumonia (9%), and acute renal failure (7%). CONCLUSIONS: Electrolyte imbalances are of particular importance in the treatment of ED patients. Therefore, ED physicians must be acknowledged of their fluid-electrolyte balance dynamics and general characteristics.