IL-12 is a key cytokine for Th1 cell development and may be important in the pathogenesis of multiple sclerosis (MS). The beta2-agonist salbutamol is known to decrease IL-12 production in monocytes of normal individuals through increased intracellular cAMP. In a prospective open-label study, we investigated by flow cytometry the effect of a 2-week long oral salbutamol treatment on monocyte IL-12 production in 21 secondary progressive MS patients. Baseline IL-12 production was higher in patients than in healthy controls. The treatment induced a significant decrease in the percentage of IL-12-producing monocytes and dendritic cells that lasted up to 1 week after treatment interruption. This first report on the use of salbutamol in MS shows that this drug has immunomodulatory properties both in vivo and in vitro, and may be beneficial in the treatment of MS.