Backgrouund: Polycystic ovary syndrome is a multifaceted disorder with a pathogenetic pathway that is not fully understood yet. Apart from hormonal derangements, insulin signaling defects and adipose tissue dysfunction, oxidative stress, defined as an imbalance derived from excessive formation of oxidants in the presence of limited antioxidants defenses, has been actively implicated in the etiology of the syndrome. Methods: This review focuses on understanding the putative role of oxidative stress in the pathophysiology of PCOS and analyzing its interconnection with the rest etiologic parameters and its contribution to the reproductive and metabolic manifestations of the syndrome. Results: Although underlying mechanisms have not been fully elucidated yet, it becomes evident that oxidative stress holds a respectable share in the pathogenesis of PCOS. In fact, PCOS can be considered as a purely oxidative state, where the body antioxidants cannot outweigh the excessive production of free radicals. Conclusion: Oxidative stress, in conjunction with the rest etiologic mechanisms of PCOS and the cardinal contribution of environmental factors, leads to an adverse redox status that stigmatizes the natural process of the syndrome.