Based on a sample of 22 oncology encounters, this article presents a discourse analysis of positive, neutral, or negative valence in the presentation of three elements of informed consent—purpose, benefits, and risks—in offers to participate in clinical trials. It is found that physicians regularly present these key elements of consent with a positive valence, perhaps blurring the distinction between clinical care and clinical research in trial offers. The authors argue that the rhetoric of trial offers constructs and reflects the complex relationships of two competing ethical frameworks—contemporary bioethics and professional medical ethics—both aimed at governing the discourse of trial offers. The authors consider the status of ethical or unethical persuasion within each framework, proposing what is called the best-option principle as the ethical principle governing trial offers within professional medical ethics.