There has been a therapeutic revolution in rheumatology over the past 15 years, characterised by a move away from oral immuno-suppressive drugs toward parenteral targeted biological therapies. The potency and relative safety of the newer agents has facilitated a more aggressive approach to treatment, with many more patients achieving disease remission. There is even a prevailing sense that disease 'cure' may be a realistic goal in the future. These developments were underpinned by an earlier revolution in molecular biology and protein engineering as well as key advances in our understanding of rheumatoid arthritis pathogenesis. This review will focus on antibody engineering as the key driver behind our current and developing range of antirheumatic treatments.