OBJECTIVES: To assess treatment patterns, resource consumption, and costs related to febrile neutropenia in patients with acute leukemia receiving chemotherapy (CT) or in ASCT recipients. METHODS: A multicentre observational cost study was conducted in 4 academic hospitals. Interim results are presented for consecutive adult patients receiving CT or ASCT between January and November 2006. FN is defined as absolute neutrophil count <0.5x109/L, fever ≥38ºC and no hint of a non-infectious fever origin. Resource use was extracted from medical patient charts. FN related costs for medication, diagnostics, blood products and re-hospitalization are presented from a hospital provider perspective. Costs for prolonged inpatient stay due to FN are excluded (under investigation). RESULTS: Of 86 patients, 46 received CT and 40 ASCT. Most common disease in CT pts was AML (78%) and in ASCT pts multiple myeloma (50%) and NHL (40%). Mean±SD age was 55±17 yrs (CT) and 57±11 yrs (ASCT). A total of 96% (CT) and 98% (ASCT) of cases respectively received neutropenia/infection prophylaxes (G-CSF, GM-CSF, antiinfectives). Mean onset of FN was 12.2±4.6 and 6.8±2.7 days following start of CT or ASCT. Mean duration of FN episodes was 5.7±4.8 days (CT) and 3.7±2.3 days (ASCT); mean treatment duration of FN was 13.3±8.2 days (CT) and 9.2±3.2 days (ASCT). A total of 91% (CT) and 95% (ASCT) of patients received antibiotics, 46% (CT) and 28% (ASCT) antifungal agents, and 83% (CT) and 85% (ASCT) blood products. Mean treatment cost per FN episode was €4,740±6,914 (Range: 0-32,455) for CT cases and €1,656±1,225 (range: 0-5,721) for ASCT cases. Main cost drivers were anti-infective drugs which accounted for 62% of cost in CT patients, and 43% of cost in ASCT patients. CONCLUSIONS: FN induces significant costs in German hospitals with highest average cost for patients with AL receiving chemotherapy.