This study estimated the annual cost of blood transfusions in the UK during 1994/1995. The analysis was based on published data, information derived from interviews with relevant NHS personnel and a purpose-designed structured questionnaire of blood donors. The cost to the UKs blood transfusion services of providing blood and blood products for transfusion was £165.5 million in 1994/1995. During this period. 2.75 million conventional donations of whole blood and 144 000 apheresis donations of platelets and plasma were collected: 2.58 million units of red blood cells were issued, resulting in ≈ 866 000 red blood cell transfusions; 334 000 units of fresh frozen plasma and 1.16 million units of platelets were issued, resulting in ≈ 17 000 and 188 000 isolated plasma and platelet transfusions, respectively. Hospital resource use attributable to providing blood transfusions during 1994/1995 cost the NHS £52.6 million. In total, blood transfusions cost the NHS £218.2 million during 1994/1995. Of this, red blood cell transfusions accounted for 76% of the annual cost, isolated platelet transfusions 16%, isolated plasma transfusions 1% and other products 7%. Donors incurred direct costs of £3.1 million and indirect costs of £11.2 million were accrued due to lost productivity. Additionally, blood donors gave up 2.5 million hours of their leisure time donating blood.