ObjectiveTo determine how current hospital practice for transfusions of red cells, platelets and fresh frozen plasma conformed with published criteria.DesignElaboration of criteria for transfusion from a review of the current literature; and analysis of the medical records of patients receiving transfusions of red cells (200), platelets (215), and fresh frozen plasma (260) during defined time periods in 1993.SettingA large tertiary care teaching hospital.Outcome measuresIn appropriateness rates for transfusion episodes and numbers of individual units of blood products administered.ResultsInappropriateness rates for transfusion episodes and numbers of individual units administered were 16% and 10% for red cells, 13% and 11% for platelets, and 24% and 16% for fresh frozen plasma (31% and 21% when transfusions for thrombotic thrombocytopenic purpura were excluded). Red cells and fresh frozen plasma were used inappropriately most frequently in association with a surgical procedure; for platelets, it was their use for bleeding. In many of the transfusions deemed inappropriate, deficiencies of red cells, platelets and/or coagulation factors were documented, but the degree of deficiency did not meet the stringent appropriateness criteria. Twenty‐six transfusions were deemed inappropriate because the indication was not documented in the medical record.ConclusionsSpecific problem areas in which blood product use was inappropriate were identified. Guidelines for transfusion appropriateness, education of hospital staff, and a monitoring system to ensure adherence to the guidelines, are required.