Percutaneous excimer laser angioplasty is dependent on a reliable and effective energy transmission through fiberoptic devices. Compared with bare fibers, ring catheters provide improved flexibility and a central channel for insertion of guide wires. Peripheral laser catheters (7-9 F) were used in 32 patients with arterial occlusive disease in the lower limbs. The technical success rate was 91%. Vessel wall dissections occurred in nine cases but caused no clinical sequelae in the preliminary follow-up period (1-6 months). The clinical application of the catheter devices proved to be safe.