Osteosarcoma is the most common malignant primary bone tumor in children and young adults and lung metastasis is the main cause of death in those patients. Deguelin, a naturally occurring rotenoid, is known to be an Akt inhibitor and to exhibit cytotoxic effects, including antiproliferative and anticarcinogenic activities, in several cancers. In the present study, we determined if deguelin would inhibit migration and invasion in U-2 OS human osteosarcoma cells. Deguelin significantly inhibited migration and invasion of U-2 OS human osteosarcoma cells which was associated with a reduction of activities of matrix metalloproteinases-2 (MMP-2) and matrix metalloproteinases-9 (MMP-9). Furthermore, results from western blotting indicated that deguelin decreased the cell proliferation and cell growth-associated protein levels, such as SOS1, PKC, Ras, PI3K, p-AKT(Ser473), IRE-1α, MEKK3, iNOS, COX2, p-ERK1/2, p-JNK1/2, p-p38; the cell motility and focal adhesion-associated protein levels, such as Rho A, FAK, ROCK-1; the invasion-associated protein levels, such as TIMP1, uPA, MMP-2. MMP-9, MMP-13, MMP-1 and VEGF in U-2 OS cells. Confocal microscopy revealed that deguelin reduced NF-κB p65, Rho A and ROCK-1 protein levels in cytosol. MMP-7, MMP-9 and Rho A mRNA levels were suppressed by deguelin. These in vitro results provide evidence that deguelin may have potential as a novel anti-cancer agent for the treatment of osteosarcoma and provides the rationale for in vivo studies in animal models.