Textile cardiovascular prostheses are woven or knitted structures made of synthetic filaments. They present particular mechanical properties linked to the nature of yarn interlacing and the wavy form of their walls. Steady and pulsatile blood flows are studied in such a prosthesis. The results show that a prosthesis cannot be considered as a fiat-walled graft. These results also demonstrate that the flow velocity near a prosthetic surface is strongly influenced by the morphology of the crimping. A local flow analysis is imperative to understanding pathologies implying hemodynamic factors and to optimizing prosthesis design.