The purposes of the International Conference on Harmonization (ICH) Good Clinical Practice (GCP) Guideline are to protect the rights of human subjects participating in clinical trials and to ensure the scientific validity and credibility of the data collected in human clinical studies. The guiding principle in the guideline is that the rights, safety, and well-being of the trial subject are the most important considerations and should prevail over the interests of science and society. The guideline will have an important and beneficial impact on the clinical trials conducted in the three participating regions (the United States, Europe, and Japan) as well as many other regions throughout the world. In the years to come, it should fulfill its intended purpose of providing for a more economical use of human, animal, and material resources and the elimination of unnecessary delays in the global development and availability of new medicines, and at the same time maintaining safeguards on quality, safety, and efficacy and regulatory obligations to protect public health.