Treatment with biological agents (biologics) has dramatically improved the outcome for patients with rheumatic diseases. However, implementation of these medications into clinical practice was associated with the high costs for the healthcare budget. Development of less expensive biosimilars of products that are no longer protected by patent and reduction in the cost of bio-originators due to increased competition provide an opportunity to expand access to effective treatment. Biologics are much more complex than conventional low-molecular drugs and cannot be copied exactly. Therefore, biosimilarity should be established, following a stepwise approach, by a series of comparative preclinical and randomised controlled studies. Phase III studies should be conducted in patients with a disease that is sensitive for detecting potential differences between the biosimilar and its bio-originator. After a biosimilar has been approved, it is necessary to gather safety and efficacy data in a much larger number of patients compared with that in phase III studies. The non-proprietary names of biosimilars and bio-originators should be readily distinguishable to facilitate postmarketing pharmacovigilance.