OBJECTIVES: Biosimilars are predicted to reduce prices of biologicals. Among biosimilars, epoetin alfa has the largest market penetration in Germany and Spain. The aim of this study was to describe the political, technological, economical and social factors that impact on epoetin alfa sales and price in both European countries, which greatly differ in their generic market size. METHODS: Revisions of regulatory legislation and policies regarding biosimilars at country and European levels have been conducted. Estimations of market shares in units for epoetin alfa originator and biosimilars plus darbopoetin alfa, a second generation biological, were calculated. Epoetin alfa pricing trend was followed. All data was extracted from IMS MIDAS database, using standard units and ex-manufacturer price. RESULTS: Both countries are under the same regulatory framework and have policies that promote generic penetration, although automatic biosimilar substitution is banned. Price of first launched biosimilar was approximately 30% below originator price in both countries. In Germany, originator price decreased about 16% after launch of second biosimilar, whereas in Spain, originator price trend have no changes to date. Regarding originator market shares, they did not change after launch of biosimilars in Spain, while in Germany marked reductions were observed along with biosimilars market share increases. In Spain, market shares of darbopoetin alfa were reduced when epoetin alfa biosimilar sales started, but no changes of the kind were documented in Germany. CONCLUSIONS: Although both countries face similar political and technological factors; in Spain, social and economical ones could negatively impact stakeholder perception. In this country, the introduction of biosimilars do not modify market share of the originator despite it has a price about 30% higher. In Germany, stakeholders pose minimum resistance to biosimilars, as market share and price of originator are immediately reduced after the entry of biosimilars.