ABSTRACT Individuals across cultures believe repeat offenders deserve greater punishment than first‐time offenders, which is also widely accepted in today's judicial system. Although previous studies indicate that children consider the transgressor's past behaviors, the effect of repeated transgressions on costly third‐party punishment remains unknown. We aimed to investigate the effects of repeated transgressions on third‐party punishment in 6‐year‐olds. We created two within‐subjects conditions: first‐time and repeated conditions, where the transgressor had transgressed for the first time, and the transgression had been repeated, respectively. In Study 1, children ( N = 43) were allowed to punish the transgressor at a personal cost. We found that more children engaged in punishment in the repeated condition than in the first‐time condition. In Study 2, we examined the effect of repeated transgressions on trait attributions and behavioral predictions regarding the transgressor with an additional group of 6‐year‐olds ( N = 43). Results revealed that repeated transgressions significantly affected behavioral prediction but did not affect trait attribution regarding the transgressor compared with the first‐time condition. These results suggest that 6‐year‐olds can administer punishment and predict a transgressor's recidivism based on the frequency information of the transgression. Our findings demonstrate that from the early stages of punitive behavior development, humans believe that repeat offenders should be strictly punished.