Oxidative stress is a quite popular subject among biochemists. With a key word search of Thomson Reuters Web of Science, a large number of entries were found starting from 1970. By using animal tissues, cell cultures or human subjects, scientists try to establish a relationship between reactive oxygen species and various situations including cancer and aging, and the protective effects of antioxidants in these cases. Some clinical trials of antioxidants are also on their way. There are several oxidative stress markers such as malondialdehyde, thiol status of the cells, superoxide dismutase, catalase and glutathione peroxidase. Although these markers are widely and continuously investigated in various laboratories, they still are not in the repertoire of a routine clinical laboratory as a biomarker of any disease. In this paper, various aspects of "oxidative stress" and antioxidants are investigated and a requirement of a radical change in the area is pointed out.