Emerging evidence suggests that cancer preventative agents might be combined with chemotherapy or radiotherapy for the more effective treatment of cancer. Recent studies suggest that genistein and other dietary compounds that prevent cancer may enhance the efficacy of cancer therapeutics by modifying the activity of key cell proliferation and survival pathways, such as those controlled by Akt, nuclear factor-kappaB, and cyclooxygenase-2. In this article, we summarize the findings of recent investigations of chemopreventive agents in combination with cancer treatment regimens.