Pentosidine is one of the advanced glycation end-products (AGEs). Its significant elevation was firstly observed in diabetes mellitus, and later found in patients with end-stage renal failure. In addition, during the aging process, pentosidine accumulates in the extracellular matrix and causes insolubility and protease resistance of extracellular matrix proteins. In cartilage, pentosidine is crosslinked in collagen and proteoglycan, and thus increases the stiffness of the cartilage. Carbonyl stress, oxidative stress and aging progress the formation and accumulation of pentosidine. In arthritis, a significant elevation of pentosidine was found in rheumatoid arthritis and moreover in osteoarthritis. This review will discuss the relationship between pentosidine and arthritis, and its role as a potential marker for arthritis.