Somatic data were collected during April 1997 on 156 females ages 6, 9, 13, and 15 years, residing in urban Pusan, South Korea, and on 158 age peers residing in rural regions surrounding the city. Comparisons were made between urban and rural groups for measures of body size and form, skinfold thicknesses, the body mass index (BMI), and estimated arm muscle area (ARM). Age at menarche was retrospectively reported by the 13- and 15-year-olds. The data were analyzed in 2 (urban-rural) x 3 (age) analyses of variance with an alpha level of P < 0.05. Age differences were evident for all dimensions. A significant main effect for urban-rural differences was found for stature, lower limb height, upper limb height, shoulder width, hip width, triceps skinfold, ARM, skelic index, and the trunk width index. Regardless of age, urban children were larger than rural children. Similar means were obtained for the BMI in urban and rural girls. Age at menarche was consistent with recent results; however, the rural sample (12.4 years) was significantly earlier than the urban sample (13.1 years). Compared with data collected four decades ago, present-day 6-, 9-, 13-, and 15-year-old females are taller and heavier at every age, indicating secular gains. Pusan females are similar in stature to age peers in Taiwan, Japan, and Hong Kong, and taller than the Chinese. Am. J. Hum. Biol. 11:735-744, 1999. Copyright 1999 Wiley-Liss, Inc.