The present study evaluated the diagnostic and predictive potential of microRNA-93 in acute ischemic stroke (AIS) patients within 6 h of stroke onset and its regulation on microglial inflammation in vitro. Our results showed that the miR-93 levels in plasma and neutrophil detected by real-time PCR were evidently reduced in AIS patients, and Pearson's correlation analysis showed that miR-93 levels in plasma and neutrophils had a significant positive linear correlation. Moreover, miR-93 levels in plasma and neutrophils of stroke patients at time of admission were not correlated with infarct volume and NIHSS (National Institute of Health stroke scale) scores at admission, but neutrophil miR-93 levels were positively correlated with the Barthel Index 7 days after stroke. Importantly, miR-93 levels in plasma and neutrophil of AIS patients were negatively correlated with the expression of TNF-alpha and IL-10. Furthermore, in vitro treatment with miR-93 agomir decreased the OGD (Oxygen and glucose deprivation)-induced proliferation of BV2 microglial cells tested by Flow cytometry. We demonstrated that miR-93 in blood has a potential to facilitate the diagnosis and prediction of neurological outcomes of acute ischemic stroke, and is involved in inflammation possibly through targeting the proliferation of microglia. (C) 2018 Elsevier Ltd. All rights reserved.