Pristane-induced arthritis (PIA) in rats is an animal model that mimics the criteria used for diagnosis of rheumatoid arthritis (RA). PIA is one of the most reproducible models of RA with high incidence and little variation in severity. Disease is characterized by a pronounced T cell dependent inflammatory response resulting in inflammation of peripheral joints. Disease is induced with a single injection of pristane and has a highly reproducible onset of arthritis between day 8-12. The most severe phase of arthritis is often between day 15-25 after induction and experiment can be terminated after 25-30 days.