Catheter device comprising a catheter (2), particularly an intravascular catheter, for insertion into an organ or vessel of the human or animal body, with a device for ablation of the adjacent organ tissue or vessel tissue using high-frequency currents in the region of the tip of the catheter, a device (3, 11, 12, 18, 19, 23, 24) being integrated for capturing images of the organ or vessel in the region of the tip of the catheter (10, 17, 22).