A treatment for prostate cancer using cyclin-dependent kinase inhibitors is provided. The effects of cyclin-dependent kinase inhibitors on the survival of prostate cancer cells was examined. Roscovitine, R-roscovitine, and CGP74514A were shown to induce the apoptosis of LNCaP and LNCaP-Rf cells, both of which express wild-type p53. The cyclin-dependent kinase inhibitors of the present invention induce the mitochondria-mediated apoptosis of prostate cancer cells by a dual mechanism: p53 accumulation and XIAP depletion.