Keeping and improving public health is a high priority aim of a modern society. In order to achieve this aim many health organizations are planning and promoting intervention programs.The proper planning of these programs demands a clear determination of factors affecting public health. It is well known that health is influenced by physical activity, physical fitness and lung function. These aspects are influenced by environmental factors. However, there is no consensus on the effect of the place of residence on physical activity, physical fitness and lung function.Therefore, the aim of this study was to examine the impact of the place of residence on physical activity, physical fitness and lung function in 12-years old schoolchildren. The sample consisted of 360 boys (189 urban and 171 rural) aged 12.3±0.42 yrs και 247 girls (125 urban 122 rural) aged 12.3±0.43 yrs. All subjects were recruited from the Greek prefecture of Trikala. The participants were assessed for anthropometrical characteristics, socioeconomic status (number of cohabitants and educational level of parents), biological maturation, last year leisure physical activity using a questionnaire (Aaron et al., 1993), physical fitness using field tests from two different batteries (Eurofit, NTSP), and lung function using the portable spirometer MicroPlus. In order to partition out differences in physical fitness and lung function due to size, allometric scaling was utilized and power function ratios were computed. To examine the impact of place of residence on anthropometric characteristics and on the number of cohabitants we utilized the t-test for independent samples on the raw data. To compare the educational level of parents and the biological maturation between urban and rural areas we utilized the χP 2 P test. To examine the impact of place of residence on physical activity we utilized the Mann-Whitney U test. To examine the impact of place of residence on physical fitness and lung function we utilized the t-test for independent samples on the computed power function ratios. Anthropometric data analysis show that body mass, BMI and sum of skinfolds were higher in urban than rural areas among boys, but there were no differences between urban and rural girls. Regarding to socioeconomic status, urban IX urban and rural children in biological maturation. Furthermore, there were no differences between urban and rural children in Vigorous Physical Activity (VPA) and Moderate to Vigorous Physical Activity (MVPA), but Moderate Physical Activity (MVA) was higher in rural than urban areas among children. The main findings concerning physical fitness data, were that only four out of the 14 possible comparisons (seven fitness parameters for boys and seven for girls) were significant different between urban and rural children. Vertical jump (VJ) was significantly higher in boys living in urban settings compared to their rural counterparts. In girls, basketball throw (BT) was found to be significantly better in the urban children, whereas hand grip strength (H...