Low birth weight has been associated with cardiovascular diseases. The waist-to-height ratio is a good indicator of risks for these diseases. The objective of this study was to examine the associations between birth weight and adult waist-to-height ratio in a Japanese population. A cross-sectional study, comprised of 851 subjects (401 men and 450 women) aged 35-62 years who were born at full term, was conducted at a medical checkup. The subjects responded to a questionnaire about weight at birth, and data on physical characteristics were collected from the results of the medical checkup. The subjects were stratified with sex and a Body Mass Index of 25 kg/m(2) to elucidate the effects of birth weight on adult waist-to-height ratio. Analysis of covariance was used to compare the physical condition among the 4 birth weight categories. After adjusting for age, alcohol consumption, smoking status and exercise, the height was significantly lower in the birth weight < 2,500 g category among men (P < 0.001) and women (P < 0.001), while the waist-to-height ratio was significantly higher in the birth weight < 2,500 g category, compared with the > 3,500 g category in the non-obese women (P = 0.004), but not in the obese women. In conclusion, low birth weight was independently associated with a low adult height among men and women and with a high adult waist-to-height ratio among non-obese women. Our results suggest that intrauterine environmental insults might lead to accumulation of visceral fat among non-obese women.