Our systematic review identified 6 publications about seeding trials and their conduct (Table): were editorials or commentaries, 2 discussed seeding trials within the context of the discussion of original research, and none directly referenced internal industry documents. In 1993, Stephens (5) characterized seeding trials as 1 of several theoretical marketing tactics used by pharmaceutical companies in postmarketing surveillance studies. Fretheim and Oxman (24) examined whether differences in prescribing patterns between the United Kingdom and Norway were caused in part by the presence of publicly funded pharmaceutical advisors in the United Kingdom as opposed to increased use of seeding trials in Norway. On the basis of communication with academic physicians, drug regulatory agencies, and medical directors of drug companies in these countries, they hypothesized that promotion of less expensive drugs by pharmaceutical advisors in the United Kingdom and the prevalence of seeding trials in Norway could help explain this disparity, although they did not provide documentary evidence. Psaty and Rennie (25) described a randomized, open-label trial of asthma medication (also a seeding trial) that used Danish national health care prescribing data (4), and represented an improvement over the nonrandomized trials described earlier by Kessler and colleagues (3). More recently, when commenting on the ENHANCE (Ezetimibe Plus Simvastatin Versus Simvastatin Alone on Atherosclerosis in the Carotid Artery) trial, Greenland and Lloyd-Jones (26) wrote that, “Trials designed for marketing purposes should not be conducted.” They raised the concern that ENHANCE may have been a seeding trial for 3 primary reasons: The trial started at approximately the same time that the FDA approved ezetimibe; it was not conducted to earn a new drug indication with the FDA; and initial reporting of results of the trial occurred almost 2 years after the trial was completed, reinforcing the lack of scientific significance. In summary, these articles call attention to the practice of seeding trials, although they do not provide documentary evidence of the existence of seeding trials.