Beraprost sodium (BPS) is a stable orally active prostacyclin analogue with vasodilatory and anti-platelet effects, and has been widely used as therapeutics for pulmonary artery hypertension and chronic arterial obstruction. In order to elucidate its effects on endothelium, we first examined the short-term effects of BPS on nitric oxide (NO) production and endothelial NO synthase (eNOS) activation using bovine aortic endothelial cells. Short-term treatment of BPS induced NO production as well as eNOS phosphorylation at Ser-1179 mediated via cAMP/protein kinase A (PKA) pathway. The effects of BPS on capillary-like tube formation were next determined using human umbilical vein ECs (HUVECs)/normal human dermal fibroblasts co-culture system. BPS was observed to induce capillary-like tube formation mediated via cAMP/PKA pathway, but not via NO generation. Finally, we performed DNA microarray analyses using RNA extracted from BPS treated HUVECs. Interestingly, BPS up-regulated several genes involved in angiogenesis, anti-atherosclerosis, and endothelial function, while down-regulated several genes involved in atherosclerosis. Our data therefore indicate that BPS may be useful not only for patients with pulmonary artery hypertension and chronic arterial obstruction, but also for general atherosclerotic patients complicated with endothelial dysfunction. Further studies are needed to clarify molecular mechanisms of these BPS effects including the involvement of peroxisome proliferator-activated receptor-delta.