The rapid development of new drugs, therapies, and devices has created a dramatic increase in the number of trials needed to properly evaluate them. The majority of patients treated today, many of whom could be eligible for participation in these studies, are seen in community hospitals and medical practices that are not affiliated with an academic medical center. Thus, there is a demonstrable need for physicians in private practice to enlist as investigators in these trials. This article is intended to encourage those physicians by describing the need and providing the rationale for their participation. It covers basic requirements for participating in clinical trials and outlines ethical, regulatory, financial, and other logistical issues of importance for the potential investigator and provides an algorithm for selecting a study for participation. Finally, the appendices review basic elements of study design and statistical principles, which may be of interest to a potential investigator.