Background: Cheating at the post-secondary level is a skewed phenomenon. While personality and environmental factors are associated with cheating, few studies account for the zero inflation when predicting cheating behaviour. Aim: In this study, we explore a person-situation interaction hypothesis where teacher autonomy support (AS) could modify the relation between students' honesty trait and premeditated cheating. Sample: Participants were 710 college students and 31 teachers. Methods: Teacher and student reports of teacher AS were collected and students also completed self-reports of honesty and premeditated cheating. Results: Given that cheating had a zero-inflated negative binomial distribution, we can investigate two separate outcomes--likelihood of cheating and magnitude of cheating. Predictably, student honesty trait predicted lower likelihood and magnitude of cheating. AS, whether student- or teacher-reported, moderated the relation between honesty and likelihood of cheating. In low perceived AS teaching environments, student honesty was associated with cheating likelihood. However, there was no such relation in high perceived AS teaching environments. Conclusions: Students' honesty generally predicts lower cheating. However, the educational environment provided by the teacher influences the strength of this association. The less autonomy-supportive students perceive the educational environment, the more their personality is important in predicting the likelihood of cheating.