Seventy three venous access ports of the same type have been implanted recently in our hospital. We have observed two cases of catheter's rupture. Both accidents show a lot of similarities: material of the same trade mark; same way of implantation: right subclavian vein; rupture before one year; rupture at the point of entry of the subclavian vein; migration of the distal part of catheter; withdrawal of this part by right femoral vein's catheterism. Both broken catheters and another not broken (implanted during more than one year) were tested. It appears that those catheters were weakened, especially around the rupture. The reason is the long-standing compression of the catheter at the narrow space between clavicle and first rib. Then, the rupture of this weakened catheter could have been produced by the high pressure due to injection with small syringes.