In this article, we analyze whether the Softwood Lumber Agreement between the United States and Canada imposed significant economic costs on industries that use softwood lumber in the United States. To ascertain this impact, we use an event study. Our event study analyzes variations in the stock prices of lumber-using firms listed at the major stock markets in the United States. We find that the news of events leading to the Softwood Lumber Agreement had significant negative impacts on the stock prices of industries using softwood lumber. The average reduction of stock prices for our sample of firms was approximately 5.42% over all the events considered. Article first published online: 20 OCT 2009