The instant invention is drawn to methods and compositions useful for the assessment of cardiovascular risk in a mammal. The methods utilize biomarkers including prostanoid metabolites and isoprostanes as sensitive and stable markers of cardiovascular risk. The methods are particularly useful in a mammal that is contemplating undergoing coxib therapy, is undergoing coxib therapy, is undergoing antioxidant therapy, has ceased coxib therapy or has never undergone coxib therapy. The invention also includes kits useful for the assessment of cardiovascular risk in a mammal.