Rheumatoid arthritis (RA) and polymyalgia rheumatica (PMR) are the most common rheumatologic diseases encountered in older patients. However, other disorders including spondylarthropathy and a variety of connective tissue diseases also occur in the elderly. PMR and the RS3PE syndrome seem to occur only in the elderly, although their symptoms may be difficult to differentiate from those of other conditions. Late-onset RA and, above all, late-onset spondylarthritis may have unusual presentations responsible for diagnostic mistakes. Pitting edema is typical of RS3PE syndrome but may also occur in other rheumatic diseases. This symptom seems to be associated with advanced age rather than with a specific cause. Because of these many unusual features, rheumatologic diseases in the elderly are often difficult to diagnose and to differentiate from a variety of other rheumatologic or nonrheumatologic conditions.