BACKGROUND World Health Organization (WHO) clinically defines a stroke as ‘the rapid development of clinical signs and symptoms of a focal neurological disturbance lasting more than 24 hours or leading to death with no apparent cause other than vascular origin’. Hypo magnesia (ionized form) leads to neuromuscular hyperirritability, tremors, increased vascular resistance, coronary vasospasm and hypertension. Magnesium deficiency triggers vasoconstriction enhancing vascular endothelial injury and hence leads to atherosclerosis. In the present study, we wanted to evaluate serum magnesium levels in ischemic cerebral stroke patients and correlate its severity with the neurological disability using modified Rankin scale (mRS) and Canadian neurological scale. METHODS It was a longitudinal observational study, undertaken in the Department of Medicine in Sri Guru Ram Das Institute of Medical Sciences and Research, Sri Amritsar from December 2018 to June 2020. 60 patients with acute ischemic cerebral stroke fulfilling the inclusion criteria were selected. 5 ml venous sample for serum magnesium level was taken within 24 hours and on day 5 of admission. Presence or absence of hypomagnesemia in patients after acute cerebral ischemic stroke was recorded during the hospital stay of patients, receiving standard management protocol of ischemic stroke. The correlation co-efficient of serum magnesium level with modified Rankin scale and Canadian neurological scale was calculated. RESULTS The mean age of patients was 61.6 ± 1.6 years, 42 (70 %) patients were male and 18 (30 %) were females and there was male preponderance. The mean serum magnesium level was measured as 1.78 ± 0.2 mg/dL, it was observed that the mean value for mRS was 3.93 ± 0.75 and Canadian neurological scale was 7.11 ± 2.01 within 24 hours and on the 5th day the mean value for mRS was 3.5 ± 1.09 and Canadian neurological scale was 8.02 ± 2.97. The present study observed a statistically significant correlation between mRS score and serum magnesium level as well as Canadian neurological scale and serum magnesium levels. CONCLUSIONS It was concluded through the results of this study that low levels of magnesium in the body can cause more severe stroke. KEYWORDS Stroke, Serum Magnesium, Hypomagnesemia, Modified Rankin Scale, Canadian Neurological Scale