The complex pathobiologic changes of human joint disease, particularly osteoarthritis (OA), normally take several decades to develop and may be influenced by a multitude of genetic and environmental factors. The need to clarify the molecular events that occur in joint tissues at the onset and during the progression of OA has necessitated the use of models, which, although imperfect, can exhibit many of the pathologic features that characterize the human disease. In vitro studies have proven invaluable in defining specific molecular and cellular events in degradation of joint tissues such as cartilage. However, to fully understand the complex inter-relationship between the different disease mechanisms, joint tissues and body systems, studying OA in animal models is necessary. Models of inflammatory arthropathies have proven predictive of clinical efficacy, with therapies that are beneficial in animals having significant benefit in treatment of rheumatoid arthritis in humans. While none of the available animal models of OA can truly be said to be predictive, as no anti-OA therapies have yet proven to be disease modifying in human trials, this approach represents a cornerstone for discovery of new anti-OA therapeutic targets and drugs. In this paper the available species and models of OA are reviewed and their potential utility discussed.