To illustrate the diagnostic problems of rheumatic disease in patients over 60 years of age, 4 cases are presented: 1) osteoarthritis, 2) late-onset rheumatoid arthritis, 3) polymyalgia rheumatica, and 4) pseudogout with crystalline synovitis. In each case the correct diagnosis should have been suspected from the history and physical examination alone, with the laboratory and x-ray findings providing supportive evidence.