Pharmacogenomics, a field of study at the interface of the disciplines of genomics and pharmacology, strives to understand the interaction between genes and the response to therapeutics. Its introduction into clinical research trials and medical practice promises to optimize the effectiveness of medications, reduce the adverse effects experienced by patients, and improve the research and development of new therapeutics. However, while pharmacogenomics promises tremendous health benefits it is still crucial to critically analyze the ethical, social and legal issues surrounding these developments. First, we present the numerous potential benefits ofpharmacogenomics. Then, using a thorough review of relevant jurisprudence, policies and literature, the main ethical, social and legal issues associated with pharmacogenomics will be identified. The likely new responsibilities for health care professionals and pharmaceutical companies as a result of pharmacogenomic development will also be discussed.