We report the case of a 25-years-old man who had an ankylosing spondylitis associated with multiple exostoses. The patient had hip pain of inflammatory origin and back stiffness with x-ray findings suggestive of bilaterral sacroilitis, coxitis as well as exostosis of the humerus, radius, femor and tibia. This is occurred in Turkey, the association was described as a simple concidence due to the difference in the genetic mechanisms involved. A more detailed genetic study of these two entities well be helpful for a better understanding of this association.