This study aimed to investigate the role of miR-877-5p in aspirin-induced gastric mucosal injury. MiRNA microarray analysis was performed using paired gastric mucosal samples to find differentially expressed miRNAs. miR-877-5p was selected for subsequent analyses. Used as a model system, gastric epithelial cells (GES-1) were transfected with miR-877-5p mimic/inhibitor, then treated with aspirin. The expression of miR-877-5p in GES-1 cells was examined using quantitative real-time PCR (qRT-PCR). Flow cytometry analysis was used to detect cell apoptosis. Western blot assay was used to measure the protein levels of PDK1. The interaction between miR-877-5p and PDK1 was determined by luciferase reporter assay. The expression of miR-877-5p in gastric mucosal injury samples was higher than that in normal samples. Also, depletion of miR-877-5p reduced the apoptosis of GES-1 cells. Luciferase reporting assay confirmed that PDK1 was a target gene of miR-877-5p. PDK1 inhibited the apoptosis of GES-1 cells treated by aspirin. Moreover, this inhibitory effect was abrogated after PDK1 knockdown. Downregulation of miR-877-5p reduced the apoptosis by targeting PDK1 in GES-1 cells treated by aspirin, indicating that miR-877-5p may be a potential therapeutic target for gastric mucosal injury caused by aspirin.