When in 1923 Jacob Viner wrote the book, Dumping: A Problem in International Trade, he probably did not imagine that the system devised to eliminate the effects of dumping (i.e., antidumping) would itself become a problem. However, as we celebrate the 100th anniversary of the first antidumping law, the situation is quite different from that observed by Viner. Although his economic analysis on the nature and causes of dumping remains valid, the debate shifted in the early 1990s and now centers on the widespread use of antidumping. This paper documents the evolution of antidumping by examining the pattern of adoptions of antidumping laws and the statistics pertaining to the worldwide caseload. One striking result is the important role played by the new users of antidumping. Rankings based on the intensity of use magnify this conclusion, suggesting that the true dimension of the antidumping phenomenon is only partly revealed by the usual statistics on usage.