OBJECTIVES: Solid organ transplants are among the most resource intensive of treatments. There exists only limited knowledge of the current costs of solid organ transplants in Canada because existing studies were derived from single centres, included different resource categories, covered different time periods, and used different cost methodologies. The purpose study was to derive population-based estimates of the direct medical costs of kidney, liver, lung and heart transplans in British Columbia (BC), Canada, from 1995 to 2003. METHODS: Province wide resource utilization data were extracted from the BC Transplant Society. This population-based registry includes records of all persons undergoing solid organ transplantation in BC. Unit cost data were obtained from publicly available sources. Health resources categories included inpatient hospital stays, outpatient visits, physician fees, laboratory and diagnostic tests and immunosuppressant medications. Mean (standard deviation (SD)) costs were derived separately for the transplant procedure and for each of the two years post-transplant and reported in 2003 Canadian dollars. RESULTS: The mean costs over all periods was $7,706 for 876 persons undergoing kidney transplant, $28,737 for 257 persons undergoing liver transplant, $43,719 for 67 persons undergoing lung transplant and $31,152 for 133 persons undergoing heart transplant. The largest component for all organs was the cost of the procedure and the initial hospitalization. The mean (SD) costs in the first and second post-discharge years were, respectively, $21,552 (326) and $11,103 (1260) for kidney, $21,146 (1273) and $8,090 (535) for liver, $27,593 (4801) and $11,426 (1144) for lung and $22,588 (1044) and $9,777 (520) for heart. Immunosuppresant medications comprised the largest single cost component during follow-up. CONCLUSION: There was six-fold variation in direct medical costs between the least and most expensive solid organ transplant procedures. The variation in costs diminished between programs over the first and second years post-transplant.