To investigate the effects of integrin-linked kinase (ILK) on gastric cancer cells both in vitro and in vivo.ILK small interfering RNA (siRNA) was transfected into human gastric cancer BGC-823 cells and ILK expression was monitored by real-time quantitative polymerase chain reaction, Western blotting analysis and immunocytochemistry. Cell attachment, proliferation, invasion, microfilament dynamics and the secretion of vascular endothelial growth factor (VEGF) were also measured. Gastric cancer cells treated with ILK siRNA were subcutaneously transplanted into nude mice and tumor growth was assessed.Both ILK mRNA and protein levels were significantly down-regulated by ILK siRNA in human gastric cancer cells. This significantly inhibited cell attachment, proliferation and invasion. The knockdown of ILK also disturbed F-actin assembly and reduced VEGF secretion in conditioned medium by 40% (P < 0.05). Four weeks after injection of ILK siRNA-transfected gastric cancer cells into nude mice, tumor volume and weight were significantly reduced compared with that of tumors induced by cells treated with non-silencing siRNA or by untreated cells (P < 0.05).Targeting ILK with siRNA suppresses the growth of gastric cancer cells both in vitro and in vivo. ILK plays an important role in gastric cancer progression.