- The aim of this study was to report six patients with palindromic rheumatism (PR) in whom signs, symptoms, and/or serologic evidence of antiphospholipid syndrome (APS) developed. The medical histories of the patients were reviewed with special emphasis on age, gender, duration of PR, and lapse of time until antiphospholipid antibodies were detected or APS was diagnosed. Three representative cases are described. Two patients were women and four were men. Their mean age was 49.3 years (range 36-80), and the mean duration of PR was 5.5 years (range 3-8). In all patients, raised titers of antiphospholipid antibodies were found on two or more occasions. Two patients developed clinical pictures compatible with APS, two showed symptoms which may be attributable for APS, and raised titers of antiphospholipid antibodies were found in only two. It seems that the appearance of these two uncommon conditions together is more than coincidental and may point to a previously unreported clinical association.