A biosimilar is a copy of an approved biological medicine whose patent protections have expired. Biosimilars of antibodies to tumour necrosis factor α (TNFα) are becoming important in the treatment of inflammatory bowel diseases (IBD). The first one introduced commercially is an infliximab biosimilar. The aim of this study was to provide an overview of anti-TNFα biosimilars. The literature on biosimilars of monoclonal anti-TNFα antibodies was reviewed, including their manufacture and approval pathways, concerns about efficacy, safety, immunogenicity, extrapolation, switching and labelling. Previous experience with biosimilars of epoetin and other growth factors was also reviewed. The infliximab biosimilar CT-P13 was the first biosimilar monoclonal antibody registered for the treatment of IBD. The major advantage of biosimilars is the reduced cost of therapy. Concerns have arisen, however, about the efficacy and safety of CT-P13 in IBD, the extrapolation of results from rheumatologic trials to IBD and the free interchangeability of CT-P13 with infliximab. Experience with simple peptide biosimilars, such as epoetins and growth factors, has generally been positive, with these biosimilars having similar efficacy and safety as the original products, although immunogenicity remains a major concern. Upcoming postregistration studies will address concerns on biosimilars in IBD, including their efficacy, safety, immunogenicity, switching and interchangeability. Biosimilars active against the same epitopes, but with improved pharmacokinetic properties that enhance their efficacy and/or safety, may be the next stage in the development of biosimilars. Anti-TNFα biosimilars represent promising new treatment options for patients with IBD. However, data on their efficacy and safety in IBD are needed.