The major development in the field of intra-arterial thrombolytic therapy over the past year was the publication of the phase II results of the Thrombolysis or Peripheral Arterial Surgery study, which compared the safety and efficacy of catheter-directed thrombolysis and surgery as the initial treatment of acute arterial occlusion. The results are consistent with those of the prior two studies, showing little or no difference between surgery and thrombolysis in the most important endpoints of survival and amputation rate. Patients receiving thrombolysis needed fewer interventions, but this benefit was balanced by increased bleeding complications. Additional studies have, therefore, been aimed at identifying subsets of patients with acute arterial occlusion who are most likely to benefit from thrombolysis. These studies have refined the selection criteria for use of thrombolytic therapy over the past year. In addition, studies have been published evaluating new drug doses and regimens aimed at broadening the scope of thrombolytic therapy in patients with acute arterial occlusion.