Patients with recurrent or relapsing arthritis are frequently seen in rheumatological practice. Besides crystal arthritis, the most frequent cause of recurrent arthritis, there are several diseases that may present clinically as intermittent mono- or polyarthritis. Palindromic rheumatism is the paradigm of this type of condition, but other diseases such as systemic autoinflammatory disorders (periodic fever syndromes), Whipple's disease, arthritis associated with hyperlipidemia, intermittent hydrarthrosis and other diseases should be taken into account in the differential diagnosis of patients with recurrent arthritis. In this chapter, we discuss recent developments in these diseases with special emphasis on palindromic rheumatism, a common condition whose close relationship with rheumatoid arthritis remains intriguing.