Lie-telling and impulsivity levels peak during late childhood to early adolescence and have been suggested to be related. Heightened impulsivity may lead adolescents to lie in favor of short-term benefits without consideration for the potential consequences of deception. The present study assessed longitudinal relations between self-reported impulsivity and lie-telling frequency. Participants from a large-scale longitudinal study (N = 1148; M[subscript age] = 11.55, SD = 1.69, 9-15 years at Time 1) reported on their impulsivity (Barratt Impulsiveness Scale) and their frequency of lie-telling to parents, to teachers, to friends, and about cheating across two time points 1 year apart. Cross-lagged path analysis revealed greater impulsivity was associated with more frequent lie-telling to parents, friends, and teachers, and about cheating over time. Our findings demonstrate the role of impulsivity in the development of lie-telling behaviors.