There are no detailed data on blood use with regard to diagnoses of recipients during infancy, childhood and adolescence. Available information on this issue is incomplete and no longer current. We conducted a survey of blood component use in children and adolescents in an acute-care university hospital in the greater area of Nuremberg between June 1994 and September 1996. Packed red blood cells (RBCs), fresh-frozen plasmas (FFPs) and platelet (PLT) components were evaluated for the recipients discharge diagnoses. Source study files were extracted from the hospital transfusion service and the medical records department. Transfused units were listed by broad diagnostic categories and leading diagnostic groups formed from principal diagnoses of the recipients according to the International Classification of Diseases, 9th edn (ICD-9). 34.3% of 2869 RBC cell units, 35.0% of 1095 FFP units and 5.0% of 1028 PLT components were used in patients with congenital diseases, mainly cardiac defects. The disease category neoplastic diseases was next most frequently associated with blood transfusion diagnosed in recipients of 23.9% of all RBCs, 15.6% of all FFP units and in 66.4% of all PLT units. Malignant diseases and benign haematological diseases (diagnostic categories II and IV) accounted for 68.9% of all costs of blood component transfusion. These findings demonstrate the increased importance of platelet transfusion for the organization of local and regional blood donation programmes and for cost analysis exercises. The study shows that detailed information on local blood use may be obtained quickly using available data collections of transfusion services and medical record departments.