Preimplantation genetics describes a newly-emerging field in medical genetics, the consequence of the implementation of clinical preimplantation diagnosis and the likely future development of germ-line gene therapy. Given the existing clinical and laboratory difficulties already demonstrated in preimplantation diagnosis and the sensitive ethical issues surrounding genetic manipulation of human embryos, there is a need for 1) critical and objective evaluation of developments in this field by human and medical geneticists and 2) development of guidelines for research and clinical practice in the years ahead. We propose a course of prospective action for preimplantation genetics implemented through the newly-formed American College of Medical Genetics in order to address the ethics, safety, accuracy, cost, and overall merit of preimplantation genetics.