Section 337 of the U.S. Tariff Act empowers the International Trade Commission (ITC or Commission) to block the importation into the United States of products that infringe U.S. intellectual property rights, including patents, copyrights, trademarks, and trade secrets. Under the ITC's pleading requirements, a Section 337 complaint filed at the ITC must "[d]escribe specific instances of alleged unlawful importations or sales." 19 CFR §210.12 (a)(3). In the past, the ITC generally instituted investigations without questioning the importation allegations in the complaint. In several recent cases, however, the ITC declined to institute an investigation as to certain proposed respondents due to inadequate pleading of importation. This article surveys those decisions and offers advice for parties filing an ITC complaint and those opposing institution of an investigation with respect to importation allegations.