The study examines the effectiveness of the impact of the Olympic education programme on declared prosocial behaviours of junior secondary school students as well as on the level of their knowledge about the Olympism. An empirical study was undertaken to assess the effectiveness. It was conducted among 138 adolescents (13-14 years old, where 62.3% were boys) attending junior secondary schools in the city of Poznan. There were three research groups: the experimental one involved in sport (n= 42), the control one involved in sport (n= 46), and the control group not-involved in sport (n= 50). The experiment was designed using the programme of the Olympic education. There were two survey instruments composed of previously validated measures. There was a statistically significant improvement in all studied variables (judgment, reasoning, intentions) of prosocial behaviours of the pupils involved in the Olympic education programme. There was also a statistically significant improvement in the level of knowledge about the Olympism among pupils involved in the Olympic education programme.