The current study examined whether age and parental reports of children's problematic lying, behavioural inhibition system (BIS) activity, and reward responsiveness predicted children's antisocial lie‐telling. Children from mostly middle and upper‐class Canadian families (ages 3–12, M = 6.23, SD = 2.52) participated in a modified Temptation Resistance Paradigm (TRP), where they were given opportunities to tell a self‐protective lie (to conceal a transgression) and an instrumental lie (to obtain a reward). Parents completed measures of their children's problematic lying tendencies, BIS activity, and reward responsiveness. Age and parent‐reported problematic lying and BIS activity were significant predictors of lie‐telling behaviour in the TRP. Instrumental liars were younger than dual liars (those who told both types of lies) and truth‐tellers. Truth‐tellers had lower parent‐reported problematic lying than instrumental and dual liars but not self‐protective liars. Dual liars had lower parent‐reported BIS activity than truth‐tellers; there were no differences among truth‐tellers, self‐protective liars, and instrumental liars. This study contributes to our understanding of the role of temperamental factors in children's lie‐telling propensity and the predictive utility of parent‐reported predictors for children's antisocial lie‐telling propensity. Our findings indicate that parents can identify and potentially address their children's problematic lying using their knowledge about their children's temperamental traits.