This paper examines the Federal quarantine established by USDA in 1996 to prevent the spread of Karnal bunt, a minor disease of wheat. During the early stages of its regulatory strategy, USDA made extensive use of probabilistic risk assessments to determine the efficacy of various quarantine protocols. However, there was less careful consideration given to the costs and benefits of the actions. If risk had been incorporated directly into the cost/benefit analysis, different conclusions would likely have been drawn about the expected impact of the regulations. This paper develops a methodology for combining these two analyses to improve future regulatory decision-making.