摘要:This study aimed to evaluate the effectiveness of an intervention entitled A-Judo Programme for the reduction in bullying and improvement of prosocial behaviour at school, based on the theory of self-determination (SDT). Physical education teachers (PETs) received 20 h of specific training, implementing the programme thereafter in their classes in a total of 10 sessions of 50 min each (two sessions per week over 5 weeks). Variables such as teacher’s teaching style, basic psychological needs (BPNs), self-determined motivation, tolerance and respect, moral identity, harassment and victimisation were studied. Seventy-nine students (11.13 ± 0.52 y) of both sexes (40 girls and 39 boys) participated in the study and were divided into an intervention and a control group (which received no training). The results showed significant changes with moderate to high effect sizes in BPN, motivation, tolerance–respect, moral identity and bullying. These research findings improve the body of knowledge of the applications offered by SDT and its usefulness for improving anti-bullying programmes through PET training.