We provide evidence that Rac1 and Cdc42 but not Rho activity is downregulated by AZA1 in prostate cancer cells and that combined Rac1 and Cdc42 inhibition suppresses cell proliferation and activation of PAK and AKT and signaling pathways affecting the downstream cell cycle regulator Cyclin D1 and the pro-apoptotic protein BAD. Here, RAC1 is linked to prostate cancer.