This study investigated the degree to which parental symptomatology and characteristics of the family environment related to posttraumatic growth (PTG) among children and adolescents who had been directly exposed to the 2004 tsunami in Thailand. One hundred five 6- to 17-year-olds (M = 11.9 years, SD = 3.3) and their parents (N = 67) were interviewed approximately 10 months and 2 years 5 months after the tsunami. The parents’ self-reported PTG was a significant predictor of PTG in their children, suggesting that social processes play a role in the development of PTG in youth. Parental self-reported posttraumatic stress symptoms did not predict PTG in their children nor did youth’s ratings of family cohesion, but parental tsunami-related sick leave related to lower levels of PTG reported by their children. Overall, these findings imply that elements of parents’ functioning can affect children’s positive adaptation after a disaster and highlight the need to assess potential parental influences and those of other sources of support in the child’s environment after trauma. Attending to such factors holds salience for efforts to promote adaptation and facilitate PTG.