The following series of papers are based on the accumulated research and practical experience of each author in one or more facets of therapeutic drug monitoring. These papers were the basis for a 2-day program sponsored by the Therapeutic Drug Monitoring and Clinical Toxicology Division of the AACC and cosponsored by the National Academy of Clinical Biochemistry. The program, The Role of Therapeutic Drug Monitoring in Disease Management, was presented at the annual AACC meeting held July 1997 in Atlanta. The primary purpose of this program was to critically examine the preanalytical, analytical, concentration–clinical response, physician education, cost/benefit, clinical outcome, measurement of pharmacodynamic responses, and new research opportunities in therapeutic drug monitoring. We hope that the reader will find these papers challenging, thought-provoking, and helpful in considering how, in the contemporary laboratory setting, we can help the process of taking therapeutic drug monitoring to the next level of practice.