This study was undertaken to determine if differences existed between pharmacologic treatments of peripheral arterial disease (PAD) with respect to PAD-related costs and health care outcomes in the United States Department of Defense health care system. We performed a retrospective review of hospital and prescription data to explore the effects of at least 90 days of aspirin, pentoxifylline, papaverine, or dipyridamole on 4 PAD-related outcomes: number of PAD-related invasive procedures (INV), number of PAD-related examination procedures (EXM), number of PAD-related hospitalization days (HDAYS), and cost of PAD-related procedures (COST) during 5 years. A covariate representing the number of PAD-related hospitalizations before the study period was used to attempt to control for severity of disease state. General linear models were used in the analyses. A statistically significant difference was seen between treatment groups for a linear combination of INV, EXM, HDAYS, and COST when controlling for past PAD-related hospitalizations (P < 0.014). A statistically significant relationship existed between treatment groups and INV (P < 0.041). The pentoxifylline treatment group had a statistically significant higher covariate-adjusted mean INV compared with the aspirin treatment group (P < 0.043). Also, PAD-related past hospitalizations were significantly related to EXM (P < 0.006). Our results appear to support the use of aspirin as a preventive treatment in PAD compared with pentoxifylline or dipyridamole.