Inflammatory processes induced by leukocytes are crucially involved in the pathophysiology of acute ischemic stroke. This study aimed to elucidate the inflammatory mechanism of long non-coding RNA (lncRNA) H19-mediated regulation of C1q and tumor necrosis factor 6 (C1QTNF6) by sponging miR-29b in leukocytes during ischemic stroke.H19 and miR-29b expression in leukocytes of patients with ischemic stroke and rats with middle cerebral artery occlusion were measured by real-time polymerase chain reaction. H19 siRNA and miR-29b antagomir were used to knock down H19 and miR-29b, respectively. We performed in vivo and in vitro experiments to determine the impact of H19 and miR-29b on C1QTNF6 expression in leukocytes after ischemic injury.H19 and C1QTNF6 upregulation, as well as miR-29b downregulation, was detected in leukocytes of patients with stroke. Moreover, miR-29b could bind C1QTNF6 mRNA and repress its expression, while H19 could sponge miR-29b to maintain C1QTNF6 expression. C1QTNF6 overexpression promoted the release of IL-1β and TNF-α in leukocytes, further exacerbated blood-brain barrier disruption, and aggravated the cerebral ischemic injury.Our findings confirm that H19 promotes leukocyte inflammation by targeting the miR-29b/C1QTNF6 axis in cerebral ischemic injury.© 2022 The Authors. CNS Neuroscience & Therapeutics Published by John Wiley & Sons Ltd.