In January 2002, the US Food and Drug Administration (FDA) issued a draft guidance requiring more detailed financial conflict of interest disclosure at advisory committee meetings. To characterize financial conflict disclosures at drug-related meetings, and to assess the relationship between conflicts and voting behavior at meetings that considered specific products. Cross-sectional study using agendas and transcripts from all FDA Drug Advisory Committee meetings (2001-2004) listed on the FDA Web site. Conflict rates, type, and size. The relationship between having a conflict and voting in favor of the index drug was described for each voter using Mantel-Haenszel relative risks and Monte Carlo simulations; Spearman rho was used for a meeting-level analysis comparing rates of conflict with voting patterns. The impact of the removal of persons with conflicts of interest on the vote margins was also evaluated. A total of 221 meetings held by 16 advisory committees were included in the study. In 73% of the meetings, at least 1 advisory committee member or voting consultant disclosed a conflict; only 1% of advisory committee members were recused. For advisory committee members (n = 1957) and voting consultants combined (n = 990), 28% (n = 825) disclosed a conflict. The most commonly specified conflicts were consulting arrangements, contracts/grants, and investments. Nineteen percent of consulting arrangements involved over 10,000 dollars, 23% of contracts/grants exceeded 100,000 dollars, and 30% of investments were over 25,000 dollars. The meeting-level analysis did not show a statistically significant relationship between conflict rates ("index conflict," "competitor conflict," or "any conflict") and voting patterns, but a weak, statistically significant positive relationship was apparent for competitor conflict and any conflict in the Mantel-Haenszel analyses. The Monte Carlo analyses produced similar findings in the competitor conflict analysis only. In all 3 conflict categories, the exclusion of advisory committee members and voting consultants with conflicts would have produced margins less favorable to the index drug in the majority of meetings, but this would not have changed whether the majority favored or opposed the drug. Disclosures of conflicts of interest at drug advisory committee meetings are common, often of considerable monetary value, and rarely result in recusal of advisory committee members. A weak relationship between certain types of conflicts and voting behaviors was detected, but excluding advisory committee members and voting consultants with conflicts would not have altered the overall vote outcome at any meeting studied.