Objectives: The purpose of the study was to evaluate the prevalence of overweight and obesity among Polish adolescents. Material and methods: Participants (13-19 years old, n = 14,044 students) were recruited from 207 schools, randomly selected from a total of 2058 schools. The stratified two-stage sampling method was used. First the schools were selected, and then the students. The study was conducted from 2013 to 2014. The body weight of students aged 13-18 years was assessed using IOTF criteria. For students aged 19 years old, standard WHO body mass index criteria were applied. Results: Excessive body weight was observed among 18.2% of all adolescents aged 13-19 years old, 11.6% were found to be overweight, and 6.6% obese. The prevalence of overweight ranged between 9.3% and 11.5% for girls, and 9.4% and 17.0% for boys. The prevalence of obesity ranged between 3.8% and 7.3% for girls, and 4.8% and 9.2% for boys. The obesity rate was higher among younger individuals for both gender groups, and a decreasing prevalence with age was observed. Conclusions: In Poland overweight was observed in one out of every eight adolescents, and obesity in one out of every 15 adolescents. The weight status was dependent on age and gender of adolescents. The highest prevalence of obesity was noted for the youngest boys (13 years old).