Background: Although proline-rich protein (PRR) 14 has been implicated in various malignancies, its involvement in stomach cancer is yet unclear. In order to improve therapeutic approaches for gastric cancer, this study intends to explore the ways in which PRR14 controls the growth and metastasis of gastric cancer cells. Methods: PRR14 expression levels in gastric cancer were analyzed using the The University of Alabama at Birmingham CANcer data analysis Portal (UALCAN) database, while the Kaplan-Meier Plotter database was used to evaluate the impact of PRR14 expression on overall survival in gastric cancer patients. After PRR14 knockdown, cell proliferation was evaluated using colony formation and cell counting kit-8 (CCK8) assays. Using flow cytometry, the rates of cell apoptosis were determined. Cell migration and invasion were assessed using transwell and wound healing assays. Protein expression in the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway was evaluated by Western blotting. Results: Significant expression of PRR14 was discovered in stomach cancer tissues, and it was associated with poor prognosis. Knockdown of PRR14 significantly reduced cell viability, colony formation, migration and invasion, while promoting apoptosis in gastric cancer cells. Furthermore, the expression levels of p-PI3K and p-Akt were markedly decreased following PRR14 knockdown. Conclusions: PRR14 knockdown inhibits the proliferation, migration and invasion of gastric cancer cells while promoting apoptosis, possibly via blocking the PI3K/Akt signaling pathway. According to these results, PRR14 might be a viable target for treatment in gastric cancer.