Oxidative stress plays a key rote in the pathophysiology of coronary artery disease, and constitutes a common mechanism behind the risk factors associated with this disease such as atherosclerosis, hypertension, diabetes and the metabolic syndrome. Oxidative stress is defined as an imbalance between the production of reactive oxygen and nitrogen species and the detoxification by the appropriate cellular systems. Reactive oxygen species induce cardiovascular dysfunction by modulating cell contraction/dilation, migration, growth/apoptosis and extracellular matrix protein turnover, which contribute to vascular and cardiac remodeling. In the last decade, the NADPH oxidase family has emerged as one of the most relevant sources of reactive oxygen species within the cardiovascular system. Recent data suggest a significant role of the genetic background in NADPH oxidase regulation. Common genetic polymorphisms within the promoter and exonic sequences of CYBA, the gene that encodes the p22(phox) subunit of the NADPH oxidase, have been characterized in the context of cardiovascular diseases. This review aims to present the current state of research into these polymorphisms with regards to their relationship to coronary artery disease.