This Practice Note discusses misleading advertising under the Competition Act, R.S.C. 1985, c. C-34. It provides an overview of the general misleading advertising provisions of the Competition Act, necessary elements to prove that a marketing claim is false or misleading, enforcement, and penalties. It also includes general overviews of several other important marketing-related sections, including relating to performance claims, promotional contests, deceptive telemarketing and ordinary selling price claims, and a misleading advertising compliance checklist.