A new multilevel infusion catheter for administration of thrombolytic agents is described that provides near equal flow distribution through each of four infusion ports. Advantages of the catheter include fluoroscopically visible infusion length markers, small size (4.7 F), and secure positioning of the catheter within the occluded segment of graft or vessel. This catheter was used for infusion of urokinase in the treatment of 20 peripheral vascular occlusions. Complete or near complete thrombolysis was achieved in all cases.