The main purpose of this study is to estimate the medical care costs of childhood and adolescent cancer in Manitoba, and to determine the elements that influence these costs. Retrospective chart reviews were done to obtain all the information. A total of 118 childhood (age 0-14 years) and 41 adolescent (age 15-19 years) cancer patients were included. For childhood cancer, in-patient hospitalizations accounted for 59% of the total cost, followed by bone marrow transplant (BMT) (9%), medications (8%), laboratory investigations (7%) and physician fees (7%). For adolescent cancer, in-patient hospitalization accounted for 37% of the total cost, followed by bone marrow transplant (BMT) (25%), physicians' fees (11%), medications (9%) and laboratory investigations (7%). Overall, the average cost for the first, second and third year following diagnosis was $50,902 (median 35,708), $13,939 (4,127) and $6,769 (2,565) respectively for childhood cancer patients, and $57,354 (24,192), $16,888 (3,267) and $3,436 (3,267) respectively for adolescent cancer patients. Further work involving long-term data linkage of medical charts with hospital and clinic financial billing codes is needed to provide more accurate estimates of the costs of childhood and adolescent cancer care.