Background:Stroke is one of the leading global causes of morbidity, death, and long-term effects. Magnesium is one of the primary intracellular divalent cations in the human body. About 25 grams of magnesium are found in a healthy adult; of this, 50% are found in the skeleton, and the remaining 1% are found in the extracellular fluid (ECF). Magnesium ions can shield neurons by preserving blood flow to the brain. It shields the brain from ischemia injury. The brain receives less blood during an ischemic stroke, depriving it of glucose and oxygen, which reduces the energy required to maintain the ionic gradients. Low magnesium levels cause vasoconstriction and damage the vascular endothelium, which accelerates the development and progression of atherosclerosis. Magnesium inhibits the accumulation of lipids in the aorta wall, slowing the progression of atherosclerosis. The severity of prognosis for stroke patients is correlated with serum magnesium levels in our study using the Modified Rankin Scoring System. Objective: To study serum magnesium levels in patients with acute stroke Materials and method: Our study is a cross-sectional, single-centred study. Patients diagnosed with acute stroke who are admitted to I.P.D. and visit Medicine O.P.D. provide data. Clinical observations, a CT scan, or Brian’s M.R.I. were used to confirm the acute stroke patients. Individuals who were admitted to the hospital with acute stroke, as confirmed by CT scan results and clinical symptoms, or Brian’s M.R.I. at OPD and IPD, were included. There will be an 18-month study period. On admission, patients are clinically examined using the Modified Rankin Scale. Measurement of magnesium 3ml of bloodis collected in a plain tube with a clot activator incubated at room temperature for 30 minutes.The centrifuge is at 3000rpm for 10 minutes at room temperature, and the serum is separated. The serum is analysed in a fully automated analyser VINTROSE5.1 by COLORIMETRIC METHOD.After the data was entered into a Microsoft Excel sheet, statistical analysis was conducted using a statistical tool for social science. A value of P < 0.05 shows statistical significance. The two-tailed approach will be used for all statistical tests. Results and discussion: Our study population consisted mainly up of male patients (73.33%). In the study population, hypertension (41.67%) was a more common risk factor than type 2 diabetes mellitus (25%), and the majority had no comorbidities at the time of presentation. The average serum magnesium level was 2.008, with a standard deviation of 0.2358. The study found a statistically significant relationship between MRS and serum magnesium levels, implying that they are inversely connected. Patients with a higher score (3 - 6) had significantly lower serum magnesium levels than those with a lower score (0 -2). (p value = <0.045). Based on our findings, serum magnesium can be utilised as a prognostic marker for acute ischemic stroke. Conclusion: Our study found that low serum magnesium levels are associated with poorer outcomes in acute stroke patients, as assessed by the Modified Rankin Scale (MRS). This shows that serum magnesium levels could be a useful prognostic marker for assessing stroke severity and predicting outcomes.