The recent introduction on the French market of Herceptin(tm), an innovative drug associated to a high acquisition cost, justifies its economic assessment. OBJECTIVE: the study aim was to compare 8 chemotherapies as first-line treatment in MBC (doxorubicin (D) + cyclophosphamide (C); 2 combinations of 5-Fluorouracile (F), Epirubicin (E) and C i.e. FEC50 and FEC100; D+paclitaxel (P); D+docetaxel (T); E+P; E+T; H+P. METHODS: The study methodology, according to a French payer perspective, is a cost-effectiveness analysis based on a decision tree model. Assessment considers the period from the diagnosis of metastasis until the end therapy or death. The clinical data are obtained from recently published phase III randomised trials. Effectiveness was assessed through time to progression criteria. Chemotherapy procedures, incidence of adverse events, patient transport and nurse care follow up were collected. Hospital costs were estimated through the National Costs References per DRG. Medication costs were estimated from standard dosages. General Nomenclature of Practitioner Acts (NGAP) was used to valuate ambulatory follow-up care. A sensibility analysis was led on efficacy criteria and main drivers cost. RESULTS: The mean cost by week without progression is €550 for H+P, €424 for E+T, €417 for E+P, €418 for D+T, €438 for D+P, €374 for FEC50, €324 for FEC100 and €365 for D+C. The most effective combination appears to be E+T, as and the financial sacrifice associated with an additional one week without progression, as compared to FEC100 for instance, is €895. Anthracyclins (D or E)+taxans (P or T) combinations show a complete dominance when compared to the H+T strategy, but the latter is only offered to the subpopulation of patients showing the receptor over-expression, a potential negative predictor for response to chemotherapy. CONCLUSIONS: Although this type of analysis favours the use of anthracyclins+taxans combinations in first-line treatment of MBC, our hypothesis has to be confirmed by clinical pharmaco-economical trials.