We have frequently observed that Beevor's sign was present in patients with facioscapulohumeral dystrophy (FSHD) but absent in patients with other neuromuscular disorders. To determine the significance of this observation we prospectively evaluated 30 patients with FSHD and 40 patients with other neuromuscular disorders. Beevor's sign was present in 27 of 30 patients with FSHD but absent in all 40 control patients. We conclude that Beevor's sign is a common finding in patients with FSHD even before functional weakness of abdominal wall muscles is apparent. Testing for Beevor's sign is a simple screening test that may help in distinguishing FSHD from other forms of facioscapulohumeral syndrome.