BACKGROUND: Bleeding and thrombotic occlusion are complications of Central venous catheters. When selecting a catheter lock solution, factors such as bleeding, thrombotic occlusion, infection, and cost-effectiveness must be considered. METHODS: The study included 35 patients who used heparin as a locking solution and 35 patients who used 0.9% saline, retrospectively. In our center, after injecting the solution equal to the catheter lumen volume from the syringe, approximately 1 cc of locking solution is left in the syringe, the catheter is locked and the syringe is removed from the catheter after locking. Intergroup complications were observed. RESULTS: No significant difference was observed between the groups concerning the catheter insertion site ( CONCLUSION: Our study concluded that heparin locking is not superior to normal saline locking in terms of catheter dysfunction. We aimed to emphasize that the technique of catheter locking is more important than the type of lock solution used.