In the present study, the effect of fatty acid synthase (FASN) inhibition on cell invasion and migration in vitro was investigated. A recombinant plasmid containing a microRNA targeting the FASN gene was used to inhibit FASN expression in U2‑OS cells. Cell migration and invasion were investigated using wound healing and Transwell invasion assays. We found that cell invasion and migration were suppressed by inhibiting FASN. In addition, the effect of inhibition of FASN on phosphorylation of Akt was investigated by detecting the expression levels of pAkt using western blot analysis. Furthermore, protein expression levels of nuclear factor‑κB (NF‑κB; p65) and matrix metalloproteinase (MMP)‑2 and ‑9 were also measured by western blot analysis. Results demonstrated that expression levels of pAkt, NF‑κB (p65) and MMP‑2 and ‑9 proteins were reduced significantly by inhibiting FASN. Therefore, we confirmed that inhibition of FASN by RNA interference suppresses osteosarcoma cell metastasis via downregulation of the phosphoinositide 3‑kinase/Akt/NF‑κB signaling pathway in vitro.