The purpose of this study was to determine if differences existed between pharmacological treatments of peripheral arterial disease (and intermittent claudication) (PAD/IC) with respect to PAD/IC-related costs and health care outcomes in the Department of Defense (DOD) health care system. METHOD: A retrospective review of hospital and prescription data was performed to explore the effects of an exposure to at least 90 days of either aspirin, pentoxifylline, or dypiridamole on various PAD-related outcomes. The outcomes under study were the number of PAD-related invasive procedures performed (INV), number of PAD-related examination procedures performed (EXM), number of PAD-related hospitalization days incurred (HDAYS), and the cost of PAD-related procedures performed (COST). The study period encompassed five years. A covariate representing the pre-study period number of PAD-related hospitalizations was used to attempt to control for severity of disease state. General linear models (GLM) were used in the analyses. RESULTS: A GLM showed a statistically significant difference among the treatment groups for a linear combination of INV, EXM, HDAYS, and COST when controlling for past PAD-related hospitalizations (p<0.02). A statistically significant relationship was also found to exist between treatment groups and INV (p<0.04). The pentoxifylline treatment group was shown to have a statistically significant higher covariate-adjusted mean INV when compared to the aspirin treatment group by a post-hoc T test adjusted for alpha inflation (p=0.04). Also, PAD-related past hospitalizations showed a statistically significant relationship with a EXM (p<0.006). CONCLUSION: The results appear to support the use of aspirin in PAD as a preventative treatment.