Several lines of evidence implicate the immune system in the pathophysiology of fibromyalgia (FM). We investigated the role of cytokines and adhesion molecules involved in immune cell trafficking and the influence of 1.5 mg of dexamethasone (DEX) per os on their expression. L-selectin was elevated on monocytes and neutrophils of FM patients. Differences in group response to DEX were observed for CD11b on NK cells, sICAM-1 and IL-2. This study shows a slight disturbance in the innate immune system of FM patients, and suggests an enhanced adhesion and recruitment of leukocytes to inflammatory sites.