Oxidative/nitrosative stress is responsible for a variety of degenerative processes in some human diseases. Measurement of oxidatively/nitrosatively modified DNA, proteins, lipids, and sugars in biological samples has been expected to detect appropriate biomarkers for diseases in which reactive oxygen/nitrogen species are involved. Recently, the application of these biomarkers to epidemiological studies has resulted in a new discipline, molecular epidemiology, which provides the opportunity for better understanding of their causal relation with disease outcomes in a population level. In this brief review, we cover some specific biomarkers of oxidative/nitrosative stress with regard to the commonly used analytical methods for these biomarkers, their integration with epidemiology, and their application in antioxidant intervention trials, with an emphasis on those applicable to human studies and their potentialities for disease prevention.