A self-expanding vascular prosthesis for implantation in a blood vessel of a patient, with a vascular prosthesis trunk having a hollow-cylindrical main body and also a first and a second opening , and with at least two vascular prosthesis side branches which branch off from the vascular prosthesis trunk and are formed integrally with the vascular prosthesis trunk , wherein the vascular prosthesis trunk has - a first, proximal vascular prosthesis trunk longitudinal portion , which comprises the first opening , a second, distal vascular prosthesis trunk longitudinal portion , which comprises the second opening , and at least two central vascular prosthesis trunk longitudinal portions which are arranged between the first and second vascular prosthesis trunk longitudinal portions and which are arranged one behind the other, and wherein the at least two vascular prosthesis side branches branching off from the vascular prosthesis trunk are arranged in the central vascular prosthesis trunk longitudinal portions , - wherein the first and second vascular prosthesis trunk longitudinal portions each have a constant diameter d1, d2 along their respective longitudinal direction and are arranged concentrically with respect to each other, and wherein the diameter d1 of the first vascular prosthesis trunk longitudinal portion is greater than the diameter d2 of the second vascular prosthesis trunk longitudinal portion , characterized in that the first and second central vascular prosthesis trunk longitudinal portions each taper toward the second vascular prosthesis trunk longitudinal portion only in one circumferential part , wherein the respectively tapering circumferential parts of the first and second central vascular prosthesis trunk longitudinal portions are arranged in a manner offset in relation to each other in the circumferential direction, and in that at least one vascular prosthesis side branch in the first central vascular prosthesis trunk longitudinal portion and at least one second vascular prosthesis side branch in the second central vascular prosthesis trunk longitudinal portion are arranged in the respectively tapering circumferential part . - a first, proximal vascular prosthesis trunk longitudinal portion , which comprises the first opening , a second, distal vascular prosthesis trunk longitudinal portion , which comprises the second opening , and at least two central vascular prosthesis trunk longitudinal portions which are arranged between the first and second vascular prosthesis trunk longitudinal portions and which are arranged one behind the other, and wherein the at least two vascular prosthesis side branches branching off from the vascular prosthesis trunk are arranged in the central vascular prosthesis trunk longitudinal portions , - wherein the first and second vascular prosthesis trunk longitudinal portions each have a constant diameter d1, d2 along their respective longitudinal direction and are arranged concentrically with respect to each other, and wherein the diameter d1 of the first vascular prosthesis trunk longitudinal portion is greater than the diameter d2 of the second vascular prosthesis trunk longitudinal portion , <EOS>