Videocapillaroscopy can be used to assess cutaneous microcirculation modifications in vivo, and therefore allows assessment of variations in the microvascular architecture in psoriatic subjects during treatment. The aim of this study was to observe and quantify the modifications of the superficial capillary bed in psoriatic plaques during treatment with cyclosporin A. Twelve patients with psoriasis vulgaris were treated with an initial dose of 4 mg/kg/day cyclosporin A over a period of 3 months with periodic clinical and capillaroscopic assessments. Clinical resolution of the lesions and a reduction in microcirculatory alterations was observed in 70% of patients, although none returned to a normal capillaroscopic pattern.