In the last decade, there has been increased recognition of the importance of disclosing and managing non-financial conflicts of interests to safeguard the objectivity, integrity, and trustworthiness of scientific research. While funding agencies and academic institutions have had policies for addressing non-financial interests in grant peer review and research oversight since the 1990s, scientific journals have been only recently begun to develop such policies. An impediment to the formulation of effective journal policies is that non-financial interests can be difficult to recognize and define. Journals can overcome this problem by providing guidance concerning the types of non-financial interests that should be disclosed, including direct research interests, direct professional interests, expert testimony, involvement in litigation, holding a leadership position in a non-governmental organization, providing technical or scientific advice to a non-governmental organization, and personal or professional relationships. The guidance should apply to authors, editors, and reviewers.