Aim: Nowadays, combination of angiotensin converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARB) with spironolactone is used to treat patients with heart failure or hypertension. Unfortunately these drugs may lead to increase in morbidity and mortality dependent on severe hyperkalemia. We aimed to evaluate the therapeutics and demographic features of patients with hyperkalemia. Methods: 39 patients with hyperkalemia were evaluated retrospectively whom hospitalized with various diagnoses. Results: Mean age and serum potassium level were (20 female and 19 male) 68.3±10.2 years and 6.8±0.7 mmol/L at admission. Twenty one patients (53.8%) used ACEI, ARB or spironolactone. The patients were divided into three groups according to their medications: patients that use anyone of the ACEI, ARB or spironolactone, patients that use combinations of these drugs and patients that do not use these drugs. The prevalence of age and diabetes were significantly high in group I and II (p=0.020 and p=0.034 respectively). Conclusion: In our study mean age and rate of the diabetics were high in group that use ACEI, ARB or spironolactone attract our attention. Therefore, patients should be carefully evaluated about older age and diabetes during prescription of these drugs (alone or in combination).