The European Medicines Agency (EMEA) workshop on biosimilar monoclonal antibodies (mAbs), held July 2, 2009 at the EMEA headquarters in London, was a harbinger with potentially far-reaching implications for all groups interested in antibody therapeutics development. These groups include not only regulators and the innovator and generic biopharmaceutical industries, but also physicians, patients and payers. The objective of the workshop was to discuss and assess the feasibility of the development and authorization of mAbs using EMEA's biosimilar regulatory pathways. The workshop sequentially focused on questions relevant to three areas: (1) chemistry, manufacturing and controls (CMC), (2) non-clinical issues and (3) clinical issues, including outcome measures. Proceedings of the workshop are presented in Part 1 of this report, and discussed within the context of the legal, regulatory and business environments of the European Union, Asia and the United States in Parts 2, 3 and 4, respectively.