OBJECTIVES: To estimate from the national database of hospital admissions in 2005, the economic burden in France of febrile neutropenia (FN) associated with myelosuppressive chemotherapy. METHODS: In France, public and private hospital admissions are recorded in administrative databases that generate Diagnosis Related Groups (DRGs), ICD10 diagnosis and procedure codes. Admissions with FN were extracted with codes combining cancer, chemotherapy, and drug-induced neutropenia. These were then categorized into those with a principal diagnosis of FN, those in which FN prolonged length of stay, and those where planned treatments were cancelled due to FN. The costs of admissions to public hospitals were obtained from an annual study of a sample group of institutions. This study is also used to generate charges to the payer (official DRG tariffs). Costs in private clinics were estimated with the 2004 reimbursement database, to which medical fees were added. Charges to the health care system were estimated with the official 2007 DRG tariffs. RESULTS: In 2005, the total number of patient admissions meeting selection criteria was 38,266 i.e. 3% of all admissions for chemotherapy. Of these, 41% were due to FN, 56% were prolonged hospitalizations because of FN and 3% were procedures cancelled due to FN. In public hospitals, the mean cost per admission due to FN was €3,636 (n=13,923), mean charge was €3,565. In private hospitals, this cost was €1,930 per admission (n=1,517). For inpatient admissions to public hospitals alone (n=9,444), the mean cost was €5,030, mean charge €4,931. Total cost to the payer for public and private admissions was €54 million i.e. 3% of the total cost for chemotherapy in France. CONCLUSION: Administrative databases can be used to estimate the economic burden of FN, a frequent complication of chemotherapy. They could be a relevant tool for studying the potential cost savings derived from appropriate preventive use of colony-stimulating factors.