Objective The aim of this study was to determine Neuropilin 1 (NRP1) contribution to transforming growth factor β1 (TGF-β1)-induced epithelial mesenchymal transition (EMT) of HGC-27 gastric cancer cells and study its mechanism.Methods In this study, TGF-β1 was used to induce EMT in HGC-27 cells. Further, these cells were stably transfected with siRNA targeting NRP1. Wound healing and transwell assays were used to measure cell migration and invasion, respectively. NRP1 and EMT markers were measured using quantitative real time reverse transcription polymerase chain reaction and western blotting. Results Exposure of TGF-β1 conferred a fibroblastic-like shape to cancer cells and significantly increased the expression of NRP1 in HGC-27 cells. TGF-β1 subsequently promoted migration and invasion of HGC-27 cells. Furthermore, silencing NRP1 inhibited the invasion and migration of TGF-β1-induced cells undergoing EMT. Conclusion Silencing NRP1 can inhibit cell migration, invasion, and metastasis and reverse the TGF-β1-induced EMT process of gastric cancer.