The use of blood and/or bone marrow stem cell transplantation (SCT) grew extensively in the last decade as technological advances led to improved outcomes and wider availability. The first study of SCT costs, however, was not published until 1989. This paper summarizes current knowledge about costs and cost-effectiveness of allogeneic and autologous SCT for leukemias and lymphoma. Methodological issues in cost studies such as types of costs, methods of data collection, and time horizons are discussed, and studies are evaluated with regard to these issues. Considerations specific to economic analyses of SCT are considered, including the potential impact of technological changes, learning curve effects, and inter-institutional differences.