AbstractThe Good Laboratory Practice (GLP) regulations are designed to provide regulatory guidance and oversight of nonclinical studies that prospectively study the effects of test articles in test systems under laboratory conditions to determine their safety. These regulations are designed to assure quality, accountability, and reliability of safety data, and provide guidelines for improving the scientific validity of the studies. A key element of the GLP regulations is with respect to the role of the Study Director, who is the individual assigned as the single point of study control and has overall responsibility for the entire nonclinical study. Experience has shown that unless responsibility for the proper conduct of a study is assigned to a single individual, the potential exists for personnel to receive conflicting instructions, and for study events and issuance of the final report to occur in an uncoordinated fashion. While serving as the Study Director can be a challenging position with numerous demands and expectations, it is a role that allows an individual the opportunity to combine project management with technical and scientific skills in the pursuit of a single goal. Individuals who serve as Study Directors in the nonclinical laboratory typically represent a diverse range of educational and professional backgrounds, and oftentimes learn to become Study Directors on the job. The goal of this paper is to provide a concise description of the Study Director's responsibilities and give guidance for planning, initiating, and completing a nonclinical study. While this paper focuses on test articles that are evaluated in the pharmaceutical/biotechnology industry and regulated by the US Food and Drug Administration (FDA) GLPs, much of the information presented should apply to other GLP and non‐GLP studies. Copyright © 2009 John Wiley & Sons, Ltd.