Biosimilars are biological medicinal products referring to an existing biological originator product and submitted to regulatory authorities formarketing authorization by an independent applicant after the patent has expired. The European Medicines Agency (EMA) has issued overarching and specific guidelines that should be fulfilled in order to receive approval as biosimilar. In accordance with these guidelines biosimilars of recombinant somatropin, epoetin alfa, and granulocyte-colony stimulating factor have gained market authorisation in the EU. Similarity in terms of quality, safety and efficacy to a reference product was demonstrated. Points to consider when switching from the innovator product to a biosimilar, or from one biosimilar to another, are reported. INN-naming, labelling, pharmacovigilance issues, interchangeability, and substitution of biosimilars are still a matter of discussion.