Fascin actin-bundling protein 1 (FSCN1) is associated with tumor progression. In addition, deregulation of the expression of FSCN1 has been observed in certain types of cancer. However, the detailed role of FSCN1 in gastric cancer remains to be elucidated. In the present study, downregulation of microRNA (miR)-133a and upregulation of FSCN1 were both observed in gastric cancer tissues and cell lines. Functional studies have revealed that miR-133a is able to bind to the 3'-untranslated region of FSCN1 mRNA, and overexpression of miR-133a causes downregulation of FSCN1 expression, while downregulation of miR-133a leads to an increased FSCN1 expression in gastric cancer cells. Furthermore, overexpression of miR-133a inhibited proliferation and invasion, but promoted apoptosis of gastric cancer cells, which may be reversed by upregulation of FSCN1. By contrast, downregulation of miR-133a enhanced proliferation and invasion, but suppressed apoptosis in gastric cancer cells. In conclusion, the anti-oncogenic activity of miR-133a may involve the inhibition of the target gene FSCN1. The present study suggested that miR-133a may be a potential therapeutic target in the treatment of gastric cancer.