Catheter fracture represents a rare problem among non-infectious complications following the insertion of totally implantable long-term central venous access systems for the application of chemotherapeutic agents. A literature survey revealed a total incidence of catheter fractures of 0-2.1%. Imminent catheter fracture can be identified radiologically, using different degrees of catheter narrowing between the clavicle and the first rib, called pinch-off sign. Two cases of catheter fracture are described and potential causes are discussed. Recommendations to avoid the pinch-off sign with the subsequent risk of catheter fracture and migration include a more lateral and direct puncture of the subclavian vein. In case of catheter narrowing in the clavicular-first rib angle, patients should be followed carefully by chest X-rays every 4 weeks. Whenever possible, the system should be removed within 6 months following insertion.