Background When the brain is deprived of oxygen and nutrients due to stenosis or arterial rupture, neurons in the affected area suffer irreversible damage and cellular death. MicroRNA has been shown to regulate target genes implicated in arterial hypertension, atherosclerosis, and diabetes mellitus, all of which influence the risk of ischemic stroke through inflammation, oxidative stress, cell proliferation, and apoptosis. The study aims to determine the changes in miRNA expression, namely miRNA-21, between acute ischemic stroke patients and controls and their relationship to proinflammatory cytokines, clinical severity, and outcome. Methods Serum samples from tertiary hospitals and controls were used to evaluate miRNA-21 expression as well as cytokines TNF-α, IL-10, ICAM-1, and CCL5 levels within 7 days of stroke onset. The 30-day clinical severity and outcome were assessed using the National Institute of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS), respectively. Result A total of 64 acute ischemic stroke patients and 22 age-matched controls were recruited, with median ages of 56 and 55.5 years old, respectively. There were more male subjects than females (35 to 29). A statistically significant difference was observed in miRNA-21 expression between patients and controls (p<0.001). This finding implies that miRNA-21 expression may have a contribution in acute stroke patients. This was followed by an increase in proinflammatory markers TNF-α, IL-10, ICAM-1, and CCL5. However, no association was found between miRNA-21 and any pro-inflammatory cytokine. There was no significant correlation between miRNA-21 or cytokines markers with clinical severity or prognosis. Conclusion Our study demonstrated increased miRNA-21 expression and proinflammatory cytokine expression in acute ischemic stroke patients relative to controls. However, this was not related to clinical severity or clinical outcomes.