The aim of this study was to determine which type of diet contributes most to plasma concentration of (+)-catechin, a naturally occurring antioxidant flavonoid. Consecutive subjects (n=180) were screened. A blood sample was collected after a fasting period and (+)-catechin measurement in plasma was performed by high-performance liquid chromatography (HPLC) method using fluorescence detection. Dietary consumption of the last evening meal was assessed by a dietary recall method. Taking fruit, vegetable and wine consumption into account, four types of diet were identified. After adjustment for confounding factors, concentration of (+)-catechin in plasma was three-fold higher in diet with fruit and vegetable but without wine (449.5 microg/l), and four-fold higher in diet with wine but without vegetable and fruit (598.5 microg/l) in comparison to diet without fruit, vegetable and wine (131.6 microg/l). When the consumption of vegetable, fruit and wine was combined, the concentration was the highest (637.1 microg/l) (P<0. 001). Vegetable, fruit and wine were the major determinants of plasma (+)-catechin concentration (P<0.001). This study demonstrates that the highest plasma concentration of (+)-catechin was observed in subjects consuming fruit, vegetable and wine, and its antioxidant and antiaggregant activity could partly explain the relative protection against coronary heart disease (CHD).