Background: As a point of departure, this study assumes that teaching to impart knowledge is inseparable from its moral role to create an ethical citizenry, such as developing standards of academic integrity. Aims: The study aims at delving into how different facets of the sense of (in)justice in the classroom may play a significant role in explaining cheating behaviour, in general, and among low-achieving students, in particular. Sample and Methods: The study was conducted among 5,084 eighth and ninth graders Israeli students. CFA and a structural modelling equations method were used to examine the study's factorial constructs and model, respectively. Results: Findings pointed to a good fit of the measurement model using SEM. In accordance with the mediating hypothesis, self-reported academic achievement was negatively related to self-reported academic cheating. Moreover, perceived 'school injustice' (procedural and distributive justice as estimates) played a mediating role in explaining the relation between academic performance and cheating behaviour. It is noteworthy, however, that the facet of the personality-like construct of justice sensitivity displayed inconsistent findings and no mediating effect when examined as a separate model. Conclusions: Self-reported academic performance and academic cheating among middle school' students were explained more strongly by contextual justice-related factors, namely perceived teachers' distributional and procedural practices in the classroom, than by justice sensitivity, which is a personality factor. Thus, teachers' justice practices seem to be crucial for developing a predisposition to academic honesty.