Maternal internalizing symptoms have been linked with child internalizing symptoms, but paternal internalizing difficulties have received little attention. Our aims were to prospectively analyse the simultaneous effect of maternal and paternal internalizing symptoms on child internalizing difficulties, examining gender differences, and to verify the mediating effect of parenting practices and child irritability. The sample included 470 families assessed at child ages 3, 6, 8, and 11. Multi-group structural equation modelling was performed with Mplus8.2. Complete equivalence was found between boys and girls for all paths. Maternal internalizing symptoms at age 3 had an indirect effect on child internalizing symptoms at age 11, via irritability at age 8. Paternal internalizing symptoms at age 3 were not associated with any of the variables under study. Maternal internalizing symptoms and child irritability are targets for intervention in order to prevent child internalizing difficulties.