In this study, we investigated the role of hematopietic progenitor kinase 1 (HPK1) in delayed neuronal damage after cerebral ischemia and the possible regulatory mechanisms of this event. Our data show that tyrosine phosphorylation of HPK1 was significantly increased at 6 h of ischemic-reperfusion compared with sham control. The increase in p-HPK1, p-MLK3, p-MKK7, and p-JNK3 was attenuated by HPK1 antisense oligodeoxynucleotides intra-cerebroventricular infusion, but not MS-ODNs or vehicle. Intracerebroventricular infusion of antisense oligodeoxynucleotides also increased the number of surviving pyramidal neurons, whereas MS-ODNs or vehicle (TE) groups had no effects. These results indicate that knockdown of HPK1 expression provides neuroprotection through downregulation activation of the MLK3-MKK7-JNK3 pathway following cerebral ischemia in the rat hippocampus CA1 subfield.