This is a new initiative to support MD postdoctoral fellows in a four year clinical pharmacology training program at Johns Hopkins. It is designed to address the widely-recognized shortage of rigorously trained physician scientists who conduct hands-on studies in humans, particularly in the area of clinical pharmacology. The program is centered in the Division of Clinical Pharmacology, a unit jointly under the Department of Medicine and the Department of Pharmacology and Molecular Sciences, in the School of Medicine. Recent leadership changes in both parent Departments and in the Division itself afford exciting new opportunities to formalize a training program that directly links molecular and clinical sciences. The proposed four year program includes a one year core curriculum in clinical pharmacology (coursework plus three research rotations) followed by three years of thesis research in the PHD-granting Graduate Training Program in Clinical Investigation. Thesis projects will include a molecular as well as a clinical component, a model used successfully with past and current trainees in the Division. Based on the collective expertise of the existing Division faculty, research is likely to focus on some aspect of anti-infective drugs, with a new emphasis on anti-parasitic agents. Each trainee will have a Primary' Mentor who will oversee the clinical aspects of the research project, complemented when appropriate by a Co-Mentor with expertise in basic science. The participating faculty includes not only those currently in the Division of Clinical Pharmacology but also a group chosen to reflect ongoing or foreseeable research collaborations and important teaching associations. The program will benefit from the advice and oversight of an Advisory Board comprised of distinguished clinician-scientists from within and outside of Johns Hopkins. Graduates from this program will have the skills and knowledge to undertake an independent career that features research in both basic and clinical pharmacology.