This study was designed to examine the relationships between birth weight or current body weight and blood pressure (BP) or cholesterol in 178 Japanese high school students (98 male, 80 female, age 15-16 yr). All subjects were born after a full-term pregnancy (gestational age ≥38wk) with a birth weight ≥2, 500g; these data were obtained from routine obstetrical records. At a health check-up, nurses used an automatic device to perform two consecutive BP measurements with each subject in a sitting position after resting for at least 5min. Serum total and high-density lipoprotein (HDL) cholesterol levels were measured. Birth weight was not related to BP, but was inversely related to serum total cholesterol in both males (r=-0.241, p<0.05) and females (r=-0.351, p<0.01). Current body weight was significantly related to systolic BP (r=0.369, p<0.01), diastolic BP (r=0.216, p<0.05), and HDL cholesterol level (r=-0.224, p<0.05) in males, but not in females. Although no relationship was demonstrated between birth weight and BP level in young Japanese students without intrauterine growth retardation, an inverse relationship between birth weight and serum total cholesterol level was found. There was a gender difference in the relationship between current body weight and either BP or HDL cholesterol in these subjects. (Hypertens Res 1999; 22: 169-172)