Cheating has received growing attention from scholars. Besides experiments carried out with university students and adults, the cheating behavior of primary school students gained less attention. We contribute to this literature by studying how students’ cheating behavior i) is influenced by ego-depletion; ii) correlates with different individual factors. We have designed an incentivized lab experiment in the field in 148 primary school classrooms at grade levels 4 to 8. We measured students’ cognitive skills, ability to delay gratification, social attitude, cheating behavior, and we gathered information about their family with an online questionnaire that students filled in at home under uncontrolled conditions. We used the widely employed dice-roll experiment to measure students’ cheating behavior. Students had incentivizes to cheat and we have modified the experiment to detect individual cheating behavior. A voluntary subsample (N = 1,043) from 126 classrooms used the online application and filled in the accompanying questionnaire. We find suggestive evidence on ego-depletion, meaning that students who received the cheating task at the end of a 20-minutes long questionnaire cheated more. We report that cheating behavior correlated weakly with students’ individual characteristics. In a multivariate context controlling for between classroom differences, we document that students’ cognitive ability correlated negatively, while their age positively, with their cheating behavior. We discuss the implication of our results in light of educational practices and formulate recommendations for future research from our design.