Trials may have stopping rules that allow early termination because of genuine (although misguided) ethical concerns. However, investigators, trial sponsors, journals, and patients may all have additional motives for stopping trials early for apparent benefit. For example, truncated trials that report a large treatment effect tend to be published in the most prestigious medical journals (1), which enhances the careers of the investigators and increases the likelihood that they will receive grants. Funding agencies have an interest in stopping trials early to minimize research costs. Pharmaceutical and for-profit sources that financially support trials are interested not only in controlling costs but also in the publicity and market share that result from reporting a trial stopped early for apparent benefit. Medical journals are interested in these trials because of publicity and citations, which result in increased journal impact factor, prestige, and advertising revenue. And patients and their advocates are motivated to stop a trial early when the experimental intervention is promising in order to hasten delivery of the intervention to clinical practice. All of these motives may affect investigators' decisions and encourage an inappropriately early stop to a trial. These considerations mandate that institutional review boards and data monitoring committees understand the principles outlined in this article and insist on appropriate standards for stopping a trial early for apparent benefit to maintain the ethical integrity of clinical trials.