One hundred eighteen consecutive patients with fibromyalgia were evaluated prospectively. Immunoglobulin deposits at the dermal-epidermal junction were found in only 4 of 36 patients. Twelve patients (14%) had at least one positive antinuclear antibody (ANA) test. Eight patients (7%) had at least one low C3. Thirty-five patients (30%) has a history of Raynaud's phenomenon and 22 (18%) had sicca symptoms, defined as symptomatic dry eyes and mouth and a positive Schirmer test. The 35 patients with Raynaud's phenomenon had a significantly higher prevalence of sicca symptoms, positive ANA or low C3 compared to the 83 patients who did not have Raynaud's phenomenon. Thus, a subset of patients with fibromyalgia may have features suggestive of a systemic connective tissue disorder.