Class of 2006 Abstract / Objectives: To determine the cost-effectiveness of urokinase (UK) and alteplase (recombinant tissue plasminogen activator, rt-PA) when used intra-arterially for the treatment of acute peripheral arterial occlusions. Methods: A decision analytic model was constructed using TreeAge Pro 2005 Suite to determine the cost- effectiveness of these therapies. Data for costs and probabilities were collected from published literature, as well as other references. Average and incremental cost-effectiveness ratios were calculated with a 95% confidence interval. A two-dimensional (sampling plus trials) Monte Carlo analysis with 5,000 patients was performed, along with a sensitivity analysis of the costs and variables. The costs measured were direct medical costs from the perspective of the healthcare institution. The primary outcome variable assessed in this model was 30-day survival. Results: The Monte Carlo microsimulation indicated that average cost-effectiveness (C/E) ratio for rt-PA was $54,141 (95th CI: 44,647 to 62,832) per successful treatment, while the average C/E ratio for UK was $65,515 (95th CI: 56,286 to 76,135). The ICER for rt-PA versus UK as the baseline was calculated to be $284,170 per additional survival over 30 days (95th CI: 186,097 to 418,443). Neither strategy was dominant. Conclusions: This study found rt-PA to be less costly but also slightly less efficacious than UK for patients treated for acute arterial occlusions. Neither therapy was indicated to be dominant over the other in terms of 30-day survival. Further long-term outcome data is necessary to more extensively assess the benefits of each therapy.