On 17 March 2000, the World Trade Organization upheld the provision in Canada's patent laws that allows generic drug manufacturers to develop (but not sell) their cheaper versions of patented medicines before the 20-year patients expire. The decision prevents pharmaceutical companies from enjoying market monopolies beyond their patent terms, avoiding what would otherwise be even lengthier delays in the sale of cheaper, generic drugs in Canada. This decision is of significance not only to Canada, but also to other WTO member countries and to all individuals who use pharmaceutical products. However, the decision is not all positive: the WTO also ruled that Canada is violating international agreements by letting generic manufacturers stockpile their versions of patented drugs before patents expire. This article explains the issues, the arguments, and the decision.