A double-weave vascular prosthesis includes an inner layer that contacts a flow of blood, and an outer layer in contact with the inner layer and having an inner layer-covering rate C (%) of 15%≦C≦75% defined by formula (1):C=[{(W1×D1+W2×D2)×25.4−W1×W2×D1×D2}/(25.4×25.4)]×100 (1),where D1 is a warp density (ends/25.4 mm) of the outer layer, D2 is a weft density (picks/25.4 mm) of the outer layer, W1 is an apparent width (mm) of a warp yarn of the outer layer, and W2 is an apparent width (mm) of a weft yarn of the outer layer, and the apparent width of each yarn is determined as a mean of measurement values for the widths of randomly selected five threads exposed on a surface of the woven structure.
