Diabetes mellitus (DM) may be accompanied by a variety of locomotor system disorders including several hand syndromes. It has been suggested that palmar flexortenosynovitis (FTS) might be included among these hand syndromes, but no conclusive data have been available. Furthermore, recent studies have indicated that FTS may be a clue to previously undiagnosed impaired glucose tolerance. In the present study the prevalence of FTS among diabetics without inflammatory rheumatic disease was 11% compared with less than 1% (p less than 0.001) in a reference group. Thus, FTS could be included among the locomotor system disorders which are associated with DM.