Prostate cancer is one of the leading causes of death in men aged 40 to 55. Genistein isoflavone (4', 5', 7-trihydroxyisoflavone) is a dietary phytochemical with demonstrated anti-tumor activities in a variety of cancers. Topotecan Hydrochloride (Hycamtin) is an FDA-approved chemotherapy drug, primarily used for secondary treatment of ovarian, cervical and small cell lung cancers. This study was to demonstrate the potential anticancer activities and synergy of topotecan-genistein combination in LNCaP prostate cancer cells. The potential efficacy and mechanism of topotecan/genistein-induced cell death was investigated. Methodology: LNCaP cells were grown in complete RPMI medium, seeded in T-25 flasks and cultured at 37C, 5% CO sub(2) for 24-48 hours to achieve 70-80% confluency. The cells were then treated with varying concentrations of genistein, topotecan and topotecan-genistein combination and incubated for 24 hours. The treated cells were assayed for i) post-treatment sensitivity using Trypan Blue Exclusion method and MTT assay, ii) classification of cellular death using Acridine Orange/Ethidium Bromide fluorescent staining and DNA Fragmentation, iii) activation of the intrinsic apoptotic pathway using Caspase 3, 8 and 9 binding assays, Mitochondrial Membrane Potential assay and Western blots of cytochrome c release and Bcl-2 expression, iv) Reactive Oxygen Species (ROS) generation levels, and Vascular Epithelial Growth Factor (VEGF) expression through RT-PCR and v) expression levels of genes using the RT super(2) Profiler[TM] PCR Array Human Apoptosis. Results: The overall data indicated that i) both genistein and topotecan induce cellular death in LNCaP cells, ii) topotecan-genistein combination was significantly more efficacious in reducing LNCaP cell viability compared to either genistein or topotecan alone, iii) in all cases, cell death was primarily through apoptosis, via the activation of the intrinsic pathway, iv) ROS levels were increased and VEGF expression was diminished significantly with the topotecan-genistein combination treatment, v) genetic analysis of topotecan-genistein treatment groups showed changes in genetic expression levels in pathway specific apoptotic genes. Up-regulation was noted through fold changes in pro-apoptotic genes, while anti-apoptotic genes had a decrease in fold changes, indicative of genetic downregulation. Conclusion: Treatments involving topotecan-genistein combination may prove to be an attractive alternative phytotherapy or adjuvant therapy for prostate cancer.