OBJECTIVES: In Brazil, health insurance companies (HIC) must offer coverage for intravenous chemotherapy drugs (IVCD), but not for oral chemotherapy drugs (OCD). We aimed to evaluate the incremental costs and the budgetary impact of the incorporation of OCD, using real world data. METHODS: We prospectively collected data during 2008, on chemotherapy usage in 14 HIC, on a population of 2 million people from different regions in Brazil. First we calculated the costs of the IVCD actually used. After that, we indentified which patients would have formal indication for OCD either as a substitutive treatment or in association with IVCD. Then, we calculated the costs associated with this intervention. Later, the budgetary impact of using OCD for eligible patients was totaled. Only drug acquisition costs were taken into account. We were conservative and assumed a “worst case scenario” (WCS) approach as the base case, therefore skewing results against OCD. RESULTS: During the one-year period, 1328 patients that received intravenous chemotherapy also had formal indication to receive OCD.   The cost of the treatment actually done was US$19,630,000. If OCD were also used, the incremental cost would be an additional US$5,500,000. The relative incremental cost associated with OCD is therefore US$2.75 per capita per year or US$0.23 per capita per month, in a WCS. CONCLUSIONS: The budgetary impact linked with the adoption of OCD is of US$0.23 per capita per month, in Brazil, according to this real world data analysis.