Excessive body mass and sedentary lifestyle are well-known factors for cardiovascular risk, which when present in the young population may have significant health consequences, both in the short- and long-term. The aim of the study was to evaluate the prevalence of overweight, obesity, and sedentary lifestyle in two teenage populations living in an urban or rural area. An additional aim was to compare their physical activity. The study was designed and conducted in 2009. The study population consisted of 116 students aged 15-17 years – 61 males (52.7%) and 55 females (47.3%), randomly selected from public junior grammar schools and secondary schools in the Poznań Region. There were 61 respondents from a rural area – 32 males (52.5%) and 29 females (47.5%), whereas 55 teenagers lived in an urban area – 29 males (47.5%) and 26 females (47.3%). Students were asked to complete a questionnaire, which was especially prepared for the study and contained questions concerning health and lifestyle. A basic physical examination was carried out in all 116 students, including measurements of the anthropometric features. Calculations were performed using the statistical package STATISTICA (data analysis software system), Version. 8.0. When comparing these two populations, no statistically significant differences were detected in the ratio of weight-growth, with the exception of the fact that the urban youths had a larger hip circumference (97.1 v. 94.3 cm, p<0.05). In the group of urban students there were also significantly more subjects with excessive body weight (27.3% v. 24.6%, p<0.05), with a predominant proportion of obese students (60%). There were significantly more male obese individuals (66.7%). In the population of rural teenagers, obesity rate did not differ statistically significantly from the percentage of overweight (11.5% v. 13.1%, p>0.05), the problem of excessive weight affected both sexes in a similar proportion (25% boys and 24.1% girls, p>0.05). In this paper it is shown that there were differences concerning physical activity of teenagers living in urban and rural areas. Urban students much more often declared an active lifestyle (72.7% v.42.6%, p>0.05), used a variety of additional forms of activity (not counting compulsory physical education classes). They also spent many more hours a week performing sport (7.0±4.2 h v. 4.9±4.1h, p<0.05), and less hours spent passively on ‘screen viewing behaviour’ (2.3±1.5h v. 3.1±1.5h, p<0.05). About 52.5% of rural teenagers replied that compulsory physical education classes were their only form of physical activity. No statistically significant differences between urban and rural population were detected in the ratio of weight-growth, with the exception of the fact that urban youths had a larger hip circumference. In the group of urban teenagers, there were significantly more subjects with excessive body weight, with a predominant proportion of obese students. However, urban students much more often declared an active lifestyle and spent many more hours a week performing sport. Their declared time for ‘screen viewing behaviour’ was shorter. These observations describing Polish teenagers are consistent with some literature data, but more studies are needed to clarify the influence of environmental conditions, such as ‘urban-rural’ differences in the health and lifestyle of the young population.