In order to examine the intergenerational transmission of reported parenting styles (warmth and control) and their mediation by personality traits, a cross-sectional questionnaire study was conducted of 396 fathers and 733 mothers of children from less tan 1 to 10 years of age. The participants used the Parental Bonding Instrument (PBI) to measure their own and their partner’s current rearing styles as well as to assess their perception of the parenting they had received before age 16. Parents’ personality traits were measured using the Temperament and Character Inventory (TCI). in both fathers and mothers, the correlation of the grandparents’ perceived parenting styles were correlated with the current parenting styles reported by parents themselves greater than with the current parenting styles reported by spouse. Thus, we speculated the shared observer bias and used the spouse-report for further analyses. In the fathers, (1) paternal Care was correlated with the grandmothers’ Care and grandparents’ low Overprotection; and paternal Overprotection was correlated with the grandfathers’ Overprotection; (2) Novelty Seeking was correlated with the grandparents’ Overprotection and low Care; Harm Avoidance was correlated with the grandparents’ Overprotection; Reward Dependence, Self-directedness, and Co-operativeness were correlated with the grandparents’ Care and low Overprotection; and Persistence was correlated with the grandparents’ Care; (3) Overprotection was correlated with Harm Avoidance and low Self-directedness. In the mothers, (1) maternal Care was correlated with the grandmothers’ Care; (2) Novelty Seeking was correlated with the grandmothers’ low Care; Harm Avoidance was correlated with the grandfathers’ low Care and the grandparents’ Overprotection; Reward Dependence, Self-directedness, and Co-operativeness were correlated with the grandparents’ Care and low Overprotection; and Self-transcendence was correlated with the grandfathers’ Care; (3) maternal Care was correlated with Reward Dependence, Persistence, and Co-operativeness; and maternal Overprotection was correlated with low Self-directedness. The transmission of Overprotection of fathers and Care of mothers from the grandparent generations was found to be mediated by personality traits.