Hyponatremia is an electrolyte imbalance common in clinical practice and is associated with impaired quality of life and survival. The aim of this study is to investigate hyponatremia-associated clinical characteristics in a hospitalized geriatric patient population. Hyponatremia was categorized as mild, moderate and severe based on serum Na levels. The relationships between severity of hyponatremia and patient age, sex, duration of hospital stay, time of hyponatremia onset and outcome were studied. A total of 978 patients aged 65 years and above were evaluated. Hyponatremia was detected in 176 patients (18%). Moderate (HR: 4.5, 95% Cl: 0.213-0.542, p<0.001) and severe hyponatremia (HR: 2.5, 95% Cl: 0.077-0.606, p<0.001) were significantly more frequent in patients with hyponatremia at the time of hospitalization. Of the etiological factors, the most common was acute renal damage and iatrogenic causes. The most common comorbidities were diabetes mellitus and hypertension. The impact of polypharmacy and impaired oral intake on hyponatremia in the geriatric population was clearly seen. We demonstrated that patients with diabetes and hypertension are at a higher risk of developing hyponatremia, and showed a significant relationship between severity of hyponatremia and the time that hyponatremia was diagnosed.