The relation between fibronectin and coronary artery disease (CAD) according to previous study results is controversial. The aim of the present study is to investigate the predictive value of fibronectin in determining the presence and severity of CAD. Patients with stable angina (n=62) who had angiographically documented CAD, and control patients (n=31) who had normal coronary angiograms, were included in the study. Plasma fibronectin levels were determined in all patients. Plasma fibronectin level (milligrams per liter) in patients with CAD was higher than normal controls (364.2+/-171 vs 265.1+/-135.5, p=0.006). The severity of CAD determined according to Gensini score and fibronectin level did not show any correlation (r=0.13, p=0.311). If fibronectin level 240 mg/l was determined as cutoff, it showed 76% sensitivity, 46% specificity, 46% negative predictive value, and 72.3% positive predictive value for predicting CAD. The present study showed that plasma fibronectin level in CAD is significantly higher than normal control subjects. However, it has no role in predicting the severity of CAD.