Rarely has the cost of heart-lung transplantation received attention. Although the procedure is still largely regarded as experimental, this does not diminish the significance of costs. The National Cooperative Transplantation Study was undertaken to better understand the costs of all transplants, including heart-lung transplantation. Data on transplantation charges from date of procedure to discharge were obtained from more than 65% of all heart-lung transplantation programs active in 1988. These programs accounted for 61% of all transplantations performed in 1988. Valid sample survey data (no more than 25 procedures per center) were obtained for 42 patients, or approximately 58% of all procedures done in the United States. Detailed data were also collected on sources of payment and amount reimbursed. Because of outlier data, we report statistical medians, rather than means, as our measure of central tendency. The median charge for heart-lung transplantation was $134,881, with an average hospital stay of 31 days. Total charges fell between $99,535 and $216,639 for 50% of the cases studied. Half of the patients spent between 23 and 49 days in the hospital. Because of the small number of cases available for analysis, it was not meaningful to cross-classify the data according to various prognostic variables. More than 78% of the procedures studied were paid for by private insurers. Reimbursement exceeded 90% of billed charges for 84.6% of the cases analyzed. Despite the experimental status of heart-lung transplantation, insurance reimbursement has been favorable for those heart-lung transplantations that insurers have covered. Nevertheless, the future of heart-lung transplantation is unclear. The availability of donors remains a serious constraint, as is seen in the decrease of procedures performed annually. In fact, lung transplantation now appears to be the preferred approach to the treatment of pulmonary disease.