The radiographic evaluation of the arthritides still relies primarily on the plain films that are readily available to every practicing clinician. The radiographic examination serves primarily to confirm the clinician's diagnosis based on the history, clinical findings, and laboratory studies and to document the severity of the arthritic changes. On occasion, the radiographic studies will be diagnostic when other findings are equivocal and the diagnosis is in question. The radiographic studies, in association with the other data, should result in a firm diagnosis greater than 90% of the time. This review article has outlined the basic features of the common arthritides and hopefully will serve as a handy reference in office practice for the evaluation of a patient with arthritis. There will always be unusual or perplexing cases that may require reference to text books devoted exclusively to the radiology of arthritis and bone disease. Of course, you can always get some excellent help by consulting with your local radiologist.