One theory suggests that anxious fathers may pose a greater environmental influence on childhood anxiety than anxious mothers. This study uses the Early Growth and Development Study (EGDS) to test rearing parent anxiety influences from mothers and fathers on child anxiety symptoms between 18 months and 4.5, while considering inherited influences. The EGDS is a longitudinal, multisite study of adopted children recruited through US adoption agencies, and their adoptive and birth parents. Bayesian latent growth models of the trajectory of child anxiety symptoms over 3 years predicted from inherited (birth parent anxiety) and adoptive parent anxiety influences were compared for maternal and paternal measures. Parameter estimates and their HPD intervals provided evidence that the slope for anxiety symptoms between 18 and 54 months is trivially affected by both rearing parent anxiety and inherited influences from both mothers and fathers. Similarly, rearing parental anxiety and inherited influence from both mothers and fathers had only a very small effect on the intercept for growth (anxiety symptoms at 18 months old). The evidence for differences between mothers and fathers for any of these parameters was, at best, weak. Contrary to theoretical predictions, anxiety in the rearing father is unlikely to have a more important role in fostering child anxiety symptoms than that in the rearing mother.