Using case studies to teach benefit-cost analysis brings out aspects of the practice of BCA that cannot be effectively taught in lectures. Case studies also allow students to demonstrate what they have learned from earlier lectures. I detail my experience using Regulatory Impact Analyses (RIAs) from the federal government, analyzed and presented by students, to reinforce lessons from lectures on the quantitative aspects of BCA and to teach lessons about how understanding an analysis is more than a mechanical exercise. Among the lessons highlighted by the case studies are how one can combine two policies to obscure the net costs of one, how precision can mask inaccuracy, the use of co-benefits and confusion about baselines. Case studies can be invaluable in presenting a holistic view of benefit-cost analysis.