Background: Magnesium (Mg) is the fourth most common cation in the human body and the second most intracellular cation after potassium. It has a fundamental role in several vital functions. As this essential ion is not measured in routine chemistry panels, little is known about its alterations during intraoperative time. Aim: The present study was designed to determine the negative effects of postoperative hypomagnesemia during and after surgeries. Subject and Methods: This study was a descriptive interventional study involving 74 patients. All patients underwent gynecological abdominal surgeries, and anesthesia protocols were standardized to comprise general and spinal anesthesia. All the patients were aged between 25 and 45 years, with ASA class I and II. Their total serum Mg level was measured 1 h before and 2 h after the surgery. The total serum Mg, calcium, and albumin level were measured by photometric methods. Data were analyzed using SPSS version 16.0 (Chicago Illinois, (USA). Inferential statistic was done using Vilksonnon‑parametric and Pearson’s correlation test. P<0.05 were considered as significant. Results: The mean serum Mg levels were 1.87 (0.32) mg/dl before and 1.55 (0.34) mg/dl after the surgeries (The normal range: = 1.7-2.5 mg/dl). Results illustrated a significant hypomagnesemia after operations. Conclusion: Clinical impact of hypomagnesemia during surgeries needs to be studied further. Moreover, surgeons should be warned about the severity of probable electrolyte imbalances induced by perioperative events to decrease associated morbidities.