Assessing and managing risks to participants is a central point of contention in the debate about disclosing individualized research results. Those who favor disclosure of only clinically significant results think that disclosing clinically insignificant results is risky and costly, and that harm prevention should take precedence over other ethical considerations. Those who favor giving participants the option of full disclosure regard these risks as insubstantial, and think that obligations to benefit participants and promote their autonomy and right to know outweigh the obligation to prevent harm or financial considerations. The risks of disclosing clinically insignificant research results are currently not quantifiable, due to lack of empirical data. The precautionary principle provides some insight into this debate because it applies to decision-making concerning risks that are plausible but not quantifiable. A precautionary approach would favor full disclosure of individualized results with appropriate safeguards to prevent, minimize, or mitigate risks to participants, such as: validating testing methods; informing participants about their options for receiving tests results and the potential benefits and risks related to receiving results; assessing participants' comfort with handling uncertainty; providing counseling and advice to participants; following-up with individuals who receive tests results; and forming community advisory boards to help investigators deal with issues related to disclosure.