The effect of dietary intake of selenium-rich food (bread, meat, eggs and fish) on plasma, erythrocytes and urinary selenium concentration was studied. plasma, erythrocytes and urinary selenium levels in healthy male (n=25) and female (n=13) subjects were determined fluorometrically and the weekly intake of seleniumrich foods was assessed using a simplified questionnaire. Geometrical mean values of selenium levels were as follows: plasma (ng/ml), 122 (male) and 118 (female); erythrocytes (ng/ml), 233 (male) and 175 (female); urine (μg/g creatinine), 25 (male) and 30 (female). Erythrocyte selenium concentrations were significantly correlated with weekly fish intake (r=0.411, p<0.05 (female+male) or r=0.453, p<0.05 (male)). Neither plasma nor urinary selenium concentrations were correlated with weekly intake of selenium-rich foad. Intake of seleniumrich food at breakfast on the day of blood or urine sampling and at supper on the preceding day were also assessed by the questionnaire. Subjects who consumed two or more selenium-rich foods at these two meals showed higher urinary selenium excretion than other subjects. These results indicate that the dietary habit of fish consumption is the main factor influencing the erythrocyte selenium concentration in Japanese, and that urinary selenium excretion is altered by intake of selenium-rich food before urine sampling.