['We have measured the pro-oxidant-antioxidant-balance (PAB) levels in patients with defined coronary artery disease (CAD) and compared them with concentrations in healthy subjects.', 'Based on angiography results, 400 patients with stable CAD were divided into CAD- and CAD+, this being further subcategorized into groups with single-, double- and triple-vessel disease (VD).', 'The mean PAB values in the healthy subjects, was significantly lower than for other groups (P<0.001). In CAD- patients, PAB levels were 123.2 ± 43.9, which was not statistically different compared to groups with SVD, 2VD and 3VD (P>0.05). In the CAD+ group, PAB values in 1VD, 2VD and 3VD were not significantly different among patients with SVD, 2VD and 3VD (P>0.05).'] Is prooxidant-anti-oxidant balance associated with extent of coronary artery disease?