Introduction: Physical education teachers’ self-efficacy seems critical in successfully including students with disabilities in mainstream classes. Despite this, many teachers state they are not prepared enough to implement inclusive Physical Education sessions for students with disabilities. Objective: This research analyzed the effects of a continuous teacher training program, Inclusive Sport at School, on their competencies and self-efficacy as determinants of the inclusion process of girls, boys, and adolescents in Chilean educational settings. Methodology: A total of 76 teachers were recruited to participate in this study voluntarily. A quasi-experimental design was adopted without a control group and pre-test and post-test measures. Results: Results showed a significant increase in subscales intellectual p<.001, physical p=.002, and visual p<0.001 disabilities of the self-efficacy variable after applying the Inclusive Sport at School program. At the same time, higher scores were found in the competence variable for all domains. Also, differences in competencies regarding the use of tasks p=.006, adapting curricular specifications p=.029, pre-active p=.024, and interaction p=.041 phase of the session. Discussion: These findings show that Physical Education teachers’ training could be decisive in including children and adolescents with educational needs in physical education classes. Conclusions: This envisions more opportunities to continue promoting training programs and to incorporate this topic into the curricula of schools that aim to follow international educational policies in terms of inclusion.