The prevalence of radiographic signs of degenerative joint disease (including appendicular osteoarthritis) among a hospital population of 218 cats was 33�9 per cent (74 cats), and the prevalence of signs of appendicular joint osteoarthritis was 16�5 per cent (36 cats). Half of the cases of appendicular joint osteoarthritis had no apparent radiographic or historical cause, and clinical signs of lameness were recorded in only six of them, all of which had an apparent radiographic cause. The 74 cats with radiographic signs of degenerative joint disease were on average significantly older than the 144 cats in which there were no radiographic signs of the disease.