The aetiology of osteochondrosis (OC) is known to be complex and multifactorial. The occurrence of bone fragments in joints and their connection to osteochondral disease are no exception. In the hock and stifle joint of the horse this type of lesion has generally been considered to be of osteochondral origin, while the process behind these fragments in the fetlock joint has been up for discussion. The objective of this study was to determine the frequency and the localisation of OC in Swedish warmblooded horses. In order to do so all radiographs of stifle, hock and fetlock joints performed on Swedish warmblooded horses during the period of 1992-1999 at Regiondjursjukhuset in Helsingborg were examined and the material was divided into two groups.