Health advocacy organizations (HAOs) are influential stakeholders in health policy. Although their advocacy tends to closely correspond with the pharmaceutical industry's marketing aims, the financial relationships between HAOs and the pharmaceutical industry have rarely been analyzed. We used Eli Lilly and Company's grant registry to examine its grant-giving policies. We also examined HAO Web sites to determine their grant-disclosure patterns. Only 25% of HAOs that received Lilly grants acknowledged Lilly's contributions on their Web sites, and only 10% acknowledged Lilly as a grant event sponsor. No HAO disclosed the exact amount of a Lilly grant. As highly trusted organizations, HAOs should disclose all corporate grants, including the purpose and the amount. Absent this disclosure, legislators, regulators, and the public cannot evaluate possible conflicts of interest or biases in HAO advocacy.