OBJECTIVES: The aims of this study were to determine the incidence of actionably high radiation dosages and to identify predictors of increased patient dosage. BACKGROUND: Peripheral endovascular intervention using fluoroscopic imaging has become a mainstay of treatment for lower extremity peripheral artery disease but exposes patients to ionizing radiation. METHODS: Patient radiation dosage, quantified as dose-area product (DAP), was obtained from the National Cardiovascular Data Registry Peripheral Vascular Intervention Registry. The percentage of procedures exceeding a DAP of 500 Gy · cm2, the threshold above which follow-up for radiation-related adverse effects is indicated by the National Council on Radiation Protection and Measurements, was determined. A multivariate regression model was generated to identify patient and procedural factors associated with increasing DAP. RESULTS: Among 17,174 procedures performed at 73 sites, patient DAP exceeded 500 Gy · cm2 in 7%. Independent predictors of increased patient DAP in order from greatest magnitude of effect included more proximal lesion location, bifurcation lesion, male sex, diabetes, hypertension, prior percutaneous coronary intervention, increasing lesion length, and increasing body mass index; antegrade vascular access, critical limb ischemia, and increasing age predicted decreased DAP. CONCLUSIONS: Radiation dosage with the potential for tissue injury occurs in 1 of every 14 patients undergoing lower extremity endovascular interventions, and all such patients are exposed to the potential for subsequent malignancy. Pre-procedural assessment of patients' risk for elevated radiation dosage may allow targeted use of radiation mitigation strategies in patients at increased risk for elevated exposure.