BACKGROUND: Human body shape is associated with the distribution of body fat and obesity-related diseases. The objectives of the study were to investigate the distribution of body shape by age and sex. Also to examine associations between body mass index (BMI) and body shape using Three-dimensional (3-D) data in Korean adults. METHODS: This study was a cross-sectional study involving 3,548 adults aged 20 years and over who participated in the Size Korea 2004. Body girths were obtained with the use of a 3-D body scan and the associations between body mass index and body shape were also obtained. RESULTS: BMI was significantly associated with waist in men and with bust in women after adjustment for age. Waist circumference was significantly associated with hip in men and with bust in women after adjustment for age. CONCLUSION: Gender difference was noted in the change of body shape with age and the associations of body shape with BMI and waist circumference in Korean adults.