A catheter system for introducing a heart valve stent into the body of a patient, the catheter system comprising: - a catheter comprising a catheter tip having a seat portion for accommodating the stent in its collapsed state and a stent holder for releasably fixing the stent, wherein the catheter is constituted by a first sleeve-shaped member and a second sleeve-shaped member, wherein the sleeve-shaped members (11, 21) are moveable relative to each other and relative to the stent holder; and - a catheter shaft for connecting the catheter tip to a handle, the catheter shaft comprising: - first force transmitting means with a distal end section forming the first sleeve-shaped member and a proximal end section connectable to first operating means of the handle; and - second force transmitting means with a distal end section connected to the second sleeve-shaped member and a proximal end section connectable to second operating means of the handle, wherein the catheter system further comprises guiding means having a guiding tube with a passageway extending therein, wherein the first and second force transmitting means (31, 41) of the catheter shaft are at least partly received within the passageway such as to be moveable relative to the guiding tube of the guiding means; and wherein the distal end of the guiding tube terminates proximal to the catheter tip of the catheter system; and wherein the first sleeve-shaped member has a cross-section equal to the cross-section of the second sleeve-shaped member. - a catheter comprising a catheter tip having a seat portion for accommodating the stent in its collapsed state and a stent holder for releasably fixing the stent, wherein the catheter is constituted by a first sleeve-shaped member and a second sleeve-shaped member, wherein the sleeve-shaped members (11, 21) are moveable relative to each other and relative to the stent holder; and - a catheter shaft for connecting the catheter tip to a handle, the catheter shaft comprising: - first force transmitting means with a distal end section forming the first sleeve-shaped member and a proximal end section connectable to first operating means of the handle; and - second force transmitting means with a distal end section connected to the second sleeve-shaped member and a proximal end section connectable to second operating means of the handle, wherein the catheter system further comprises guiding means having a guiding tube with a passageway extending therein, wherein the first and second force transmitting means (31, 41) of the catheter shaft are at least partly received within the passageway such as to be moveable relative to the guiding tube of the guiding means; and wherein the distal end of the guiding tube terminates proximal to the catheter tip of the catheter system; and wherein the first sleeve-shaped member has a cross-section equal to the cross-section of the second sleeve-shaped member. - first force transmitting means with a distal end section forming the first sleeve-shaped member and a proximal end section connectable to first operating means of the handle; and - second force transmitting means with a distal end section connected to the second sleeve-shaped member and a proximal end section connectable to second operating means of the handle, wherein the catheter system further comprises guiding means having a guiding tube with a passageway extending therein, wherein the first and second force transmitting means (31, 41) of the catheter shaft are at least partly received within the passageway such as to be moveable relative to the guiding tube of the guiding means; and wherein the distal end of the guiding tube terminates proximal to the catheter tip of the catheter system; and wherein the first sleeve-shaped member has a cross-section equal to the cross-section of the second sleeve-shaped member. wherein the catheter system further comprises guiding means having a guiding tube with a passageway extending therein, wherein the first and second force transmitting means (31, 41) of the catheter shaft are at least partly received within the passageway such as to be moveable relative to the guiding tube of the guiding means; and wherein the distal end of the guiding tube terminates proximal to the catheter tip of the catheter system; and wherein the first sleeve-shaped member has a cross-section equal to the cross-section of the second sleeve-shaped member.