This study examined the effect of child gender on the bidirectional relationships between perceived parental monitoring and self-reported delinquent behaviors from childhood to adolescence, using data from the Korean Youth Panel Study. In this longitudinal study, different age cohorts for childhood (ages 9–12; N = 2283) and adolescence (ages 13–16; N = 2722) were analyzed. The findings from cross-lagged path analyses showed that the parent–child relationships differed for boys and girls. For girls, delinquency had a stronger effect on parental monitoring in childhood, whereas parental monitoring had a stronger effect on delinquency in the childhood–adolescence transition and adolescence. Boy’s delinquency similarly had a stronger effect in childhood. Parental monitoring, however, did not affect boy’s delinquency at any age. This study highlights the importance of considering gender when developing interventions to support families with delinquent children and adolescents.