Raynaud's phenomenon is the most common sign of vascular involvement in scleroderma. Careful clinical evaluation using a simple definition of Raynaud's phenomenon is the most reliable and reproducible method in the diagnosis. The assessment of microvascular function by laboratory methods is still not specific or sensitive enough for individual patient evaluation. The study of mechanisms involved in the pathogenesis of primary and secondary Raynaud's phenomenon offers the best window for investigation of the early pathogenetic stages in scleroderma. The structural vascular disease in scleroderma is well documented. Still, the impact of endothelial involvement on organ functions is just beginning to be identified and appreciated. Dysregulation of vascular tone control and deficiency of the vasodilatory neuropeptides in scleroderma is proposed as a mechanism in the development of Raynaud's phenomenon. Decreased fibrinolysis and enhanced platelet aggregation is documented and undoubtedly contributes to microvascular thrombosis. The nature of endothelial injury is still elusive, yet markers of endothelial activation and injury continue to be described. Therapy directed toward the vascular disease continues to focus on the alleviation of vascular spasm. Calcitonin gene-related peptide is the newest agent in our therapeutic armamentarium.