The invention relates to a device (1a-1d) for compressing a stent (100) or a stent (100) with a prosthetic heart valve affixed thereto. The invention further relates to a system as well as a method for loading a stent (100) into a medical delivery system. The device (1a-1d) according to the invention comprises a compressing mechanism (10a-10d), within which a stent (100) to be compressed can be at least partly accommodated, wherein the compressing mechanism (10a-10d) comprises externally- manipulatable clamping means (50； 70.1-70. n； 90.1-90. n； 110.1-110. n) and is designed so as to exert a compressive force in radial direction on at least parts of a stent (100) accommodated within the compressing mechanism (10a-10d) such that the cross-section of the stent (100) is reduced to a predefinable value at least at certain areas. The inventive device (1a-1d) further comprises a manipulating mechanism (40a-40d) for manipulating the at least one clamping means (50； 70.1- 70. n； 90.1-90. n； 110.1-110. n), said manipulating mechanism (40a-40d) being moveable relative to the compressing mechanism (10a-10d) for moving the at least one clamping means (50； 70.1-70. n； 90.1-90. n； 110.1-110. n) in the radial direction in order to adjust the internal cross-sectional diameter of the compressing mechanism (10a-10d).L'invention concerne un dispositif (1a-1d) de compression d'une endoprothèse (100) ou d'une endoprothèse (100) possédant une valvule cardiaque prothétique fixée dessus. L'invention concerne en outre un système ainsi qu'un procédé de chargement d'une endoprothèse (100) dans un système d'administration médicale. Le dispositif (1a-1d), selon l'invention, comporte un mécanisme de compression (10a-10d) à l'intérieur duquel une endoprothèse (100) devant être comprimée peut être au moins partiellement logée, le mécanisme de compression (10a-10d) comportant des moyens de serrage pouvant être manipulés extérieurement (50 ； 70.1-70. n ； 90.1-90. n ； 110.1-110. n) et étant conçu de
