OBJECTIVES The expiration of biotech drugs patents has led to the creation of drugs copies of originator products, defined biosimilars. The automatic substitutability between the originator and the biosimilar is not allowed in Europe with the exception of France. In Italy, in the absence of a national legislation, some Regions have issued directives to the spread of the biosimilar use. Campania was the first Region to legislate on the matter, supporting the prescription of the biosimilar to the naive patient. The aim of this study was to evaluate the impact of cost-containment policies about biosimilars in Campania between 2009 and 2013. METHODS IMS Health regional database was used to carry out this descriptive retrospective drug-utilization for the years 2009 through 2013. Information was retrieved about different distribution channels (retail, direct distribution, hospital). Consumptions are expressed in Counting Units (CU) and trends have been calculated using Compound Average Grow Rate (CAGR).   RESULTS In 2013, a total consumption of 930.859 CU of biosimilar drugs was registered in Italy (CAGR 13/09 68,8%). The penetration rate of biosimilar was 23,9% with regard to expenditure and 25,3% with regard to consumption. Analyzing the consumption of biosimilars by therapeutic category in Italy, the consumption of erythropoietin and filgrastim has an index of annual growth respectively equal to 153.4% and 174.7%. In Campania, the penetration rate of all biosimilars was 31.4% of total expenditure and 35.9% of consumption. Analyzing the trend in consumption for single therapeutic category, it can be seen that penetration is due to erythropoietin (297.5% CAGR); with regard to filgrastim, however, the average annual growth rate is around 54%. CONCLUSIONS The results suggest that Campania Region records an index of market penetration of biosimilars higher than the national. This trend could be attributable to the cost-containment policies implemented in the region.