OBJECTIVES: The cost of drugs for cancer treatment continues to increase, especially with the addition of monoclonal antibodies and other targeted therapies to standard cancer treatment regimens. The purpose of this study was to examine the pharmaceutical expenditure growth in anticancer drugs in Catalonia between 2003 and 2007. METHODS: Data from the Pharmaceutical Care and Complementary Benefits database from the Catalan Health Service was used. This database contains information on all drugs dispensed in the outpatient setting in public hospitals. Drug expenditure was not adjusted for inflation and results are expressed in nominal terms. RESULTS: From 2003 to 2007, total drug expenditure (TDE) grew at an average annual rate of 13.4%. During this period mean average growth rate for total anticancer drug expenditure (TACDE) was 46.1% increasing  from 24,8 million Euros in 2003 to €111.6 million in 2007. TACDE as percentage of TDE increased over the 5-year period from 9% in 2003 to 22.6% in 2007. Considerable variation in growth of TACDE was observed across regions and hospitals. Six drugs (trastuzumab, imatinib, docetaxel, oxaliplatin, rituximab and paclitaxel) accounted for 67% of TACDE. The number of patients receiving anticancer drugs and the number of dispensed drugs increased by 29,13% and 34,2%, respectively. Per patient anticancer drug expenditure increased from €3.896/patient in 2003 and €6.220/patient in 2007. Information in diagnosis was not available and analyses per type of cancer could not be performed. CONCLUSIONS: Anticancer drug expenditure in the outpatient setting has been increasingly growing during the study period.  Both the volume of drug use and the entry of new drugs (typically introduced to the market at higher prices) seem to be explanatory factors determining drug spending trends in Catalonia. A more comprehensive approach to the use of anticancer drugs by type of cancer is of high importance.