A Yersinia pseudotuberculosis serotype III outbreak in 1982 was characterized by a high frequency of post-infectious complications. Ten years later 16 out of the 19 patients originally included in the outbreak were reached for a follow up evaluation. Altogether nine patients suffered from chronic joint symptoms. Four of them were HLA B27-positive. Two of these had ankylosing spondylitis; one with severe erosive polyarthritis and secondary amyloidosis which led to uremia requiring haemodialysis and eventually to death, the other with ankylosis of the lumbar spine and sacroiliitis. None of the patients any longer had detectable anti-Yersinia antibodies. The long-term prognosis of Yersinia-triggered reactive arthritis is discussed.