Vascular endothelial growth factor (VEGF) is known to be involved in the pathogenesis of POEMS (polyneuropathy, organomegaly, endocrine disorder, M-protein, and skin lesion) syndrome. Because platelets have recently been recognized as transporters of VEGF, enhanced blood coagulation activity in this syndrome may accelerate vasopermeability by releasing VEGF from platelets in vivo. Here we report a case of POEMS syndrome with anasarca showing a high ratio of serum VEGF to platelet count, indicative of massive VEGF release from aggregated platelets in vivo. Changes in the ratio clearly reflected disease activity. This observation suggests that the ratio of serum VEGF to platelet count is more precise in monitoring disease activity than serum VEGF alone, and that VEGF released in vivo is critically involved in the pathogenesis of POEMS syndrome, causing hypervasopermeability.