Basic science and medical journals are increasingly requiring authors to disclose financial interests they have in the subject matter of contributed articles and letters. A comparison of journal conflict-of-interest (COI) policies can provide insight into published reports of low compliance rates and inconsistencies in disclosures by the same author found in different journals. The objective of this article is to compare the criteria, specificity, and scope of COI polices in toxicology and medical journals. We studied the COI policies of 47 toxicology and 180 medical journals catalogued in Ulrich's International Periodicals Directory for criteria of competing interests, types of submissions covered, monetary or time thresholds for reporting, and penalties for violations. Indicators were constructed for rating policy specificity, author discretion, and policy scope. Written COI policies were found in 87% if the toxicology and 84% of the medical journals; 15% and 28% of the toxicology and medical journals, respectively, were explicit about the type of content covered by the policy; 20% and 29%, respectively, included a monetary threshold for reporting purposes; the level of author discretion for reporting COIs was found to be high in 46% of the toxicology and 41% of the medical journals respectively. The level of specificity for more than 75% of the written journal COI policies for both fields was minimal or practically nil, and the scope of more than 80% of the policies was minimal to narrow. Lack of specificity, high author discretion, and restricted scope were found to be prevalent among COI policies of toxicology and medical journals.