In an era of health care reform, costs, cost-effectiveness and charges for health care are taking on a larger role in the decision to adopt a new therapy. Hospitals, health maintenance organizations, third-party payers, doctors and patients all have an interest in the economic factors of health care; however, not all new therapies or medications have been analyzed. Bone marrow transplantation is one of the most expensive cancer treatments, costing an average of +193,000 per patient; therefore, many economic studies have focused on the costs of the therapy. However, it is important to note that these findings are not necessarily applicable to other diseases. Cost data are not static and even small changes in protocol can make a large difference in costs. Also, cost data from outside the United States is not always applicable to the United States system due to differences such as socialized medicine, workers' wages and pharmaceutical costs. Many economic analyses focus on the hospitals' charges and extrapolate cost-effectiveness from these figures, yet the amount hospitals charge for services and products is not always relative to the costs. Therefore, third-party payer costs are also important in analyzing the cost-effectiveness of a procedure. This article will review five signature papers which illustrate important issues to consider when trying to determine the costs and cost-effectiveness of bone marrow transplants.