Introduction: Hyponatremia is commonly seen in inpatient care; however, the availability of data regarding the prevalence of hyponatremia in the elderly in Jeddah, Saudi Arabia is insufficient.Objectives: The objective of this study is to estimate the prevalence of hyponatremia in a sample of older inpatients.Materials and Methods: A retrospective chart review conducted in a tertiary care hospital, Jeddah, Saudi Arabia included all patients 60 years and older who were admitted to the internal medicine department between January 2017 and November 2020. Patients with hyponatremia were identified by looking through the hospital's laboratory database of inpatients. Patients' demographics, serum sodium level, medication history, and disease history were recorded and those with pseudohyponatremia were excluded.Results: During the study period, 322 out of a total of 2,893 elderly patients admitted to the internal medicine department were diagnosed with hyponatremia (11.1%). Of these patients, 183 (56.8%) were female and 139 (43.2%) were male. Hyponatremia was more prevalent in patients with cardiovascular diseases (84.2%), followed by endocrine diseases (73.3%). The most prescribed medications for the studied hyponatremic patients were proton pump inhibitors (38.8%), diuretics (29.8%), angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (22.4%), all of which are commonly known to be associated with hyponatremia.Conclusions: Hyponatremia has severe consequences if left untreated. Therefore, estimating the prevalence of this condition in the older population will direct more clinical attention to evaluate the serum sodium level on a regular basis. It is recommended that future studies focus on finding an association between hyponatremia and older patients with multi-drug usage as well as identifying the causes of hyponatremia.