This study evaluated a predictive model of school participation based on Ajzen’s theory of planned behaviour. Attitudes towards social justice, perceived control and subjective norm on school participation were tested, mediated by the behavioural intention in favour of social justice in a sample of 443 secondary school students. The proposed model showed good fit (χ 2  = 597.740, df = 342; RMSEA = .041). The behavioural intentions towards social justice and perceived behavioural control were directly related to school participation. An indirect effect of perceived control on participation was detected, mediated by behavioural intention, but no evidence was found of the indirect effect of either attitude or norm on school participation.