Rapidly destructive arthritis with relatively noninflammatory joint fluids has been described at shoulders as well as at other large joints under a variety of names in older persons. Because this syndrome frequently is not recognized, we have reviewed our experience with such cases. After excluding patients with known causes such as avascular necrosis, Paget's disease, neuropathic arthropathy, endocrine disorders, radiographic evidence of chondrocalcinosis, and hemodialysis, we have seen 20 such patients who are described in this report. All were over age 67, and 16 were women. Seventeen patients had shoulders involved; 6 had destructive arthritis at the knees. Many other patients had multiple sites affected. Six patients also had erosive osteoarthritis of small joints.All patients had diffuse cartilage loss and juxta-articular bone destruction. Patients had been symptomatic a mean of 3.5 years at the time of the study. Bony sclerosis on x-ray was more common than reported in previous series. Joint effusions were bloody or clear. All fluids had strongly positive alizarin red S positive chunks; apatites were confirmed in all 7 studied by electron microscopy. Nine had calcium pyrophosphate dihydrate crystals. The latter were somewhat more commonly associated with bony sclerosis, but crystal types did not explain all differences seen in x-ray patterns.Destructive arthropathy of the elderly involves many large joints in addition to the shoulders, and some patients also have erosive osteoarthritis of fingers. Although calcium pyrophosphate dihydrate crystals were present in many patients along with apatites, the role of crystals is not clear. Radiographic patterns may be more diverse than previously suggested by some researchers, so that the spectrum of idiopathic destructive arthritis reported may depend on selection criteria. It is important to be aware of this noninfectious cause of severe joint destruction at a variety of joints.