Children who are more fearful and inhibited during early childhood are at greater risk for social problems (e.g., loneliness, social isolation) and clinically significant internalizing disorders during adolescence and adulthood (e.g., Rubin, Chen, McDougall, Bowker, & McKinnon, 1995; Williams et al., 2009). While the impact of fearful temperament on adjustment indices are regularly the focus of study, less well understood are biological and social processes that may affect the development of fearful temperament. The present study considered the role of the 5-HTTLPR polymorphism and parenting on change in fearful and inhibited temperamental characteristics during early childhood. The s/s genotype was expected to be associated with elevated and sustained levels of fearful temperament. Moreover, supportive parenting was expected to be associated with less fearful temperament while more harsh parenting would be associated with more fearful temperamental characteristics, especially for children with the s/s 5-HTTLPR genotype. Study hypotheses were tested using 165 families (i.e., biological mothers and fathers, 3-5 year old children) who participated in the Family Transitions Project (FTP: R. D. Conger & K. J. Conger, 2002). Children were genotyped using cheek swabs. Parents reported on children’s temperamental characteristics at ages 3, 4, and 5. Independent observations of mothers and fathers completing a puzzle with their 3 and 4 year old children were used to measure parenting. Results were partially supportive of predictions. Parenting interacted with the 5-HTTLPR genotype to predict trajectories of shyness and soothability dimensions of fearful temperament, but the pattern of findings varied for mothers and fathers. Results are discussed in terms of differential susceptibility and the conceptualization of risk and resilience.