Deployment to war is associated with disruptions to emotion regulation and parenting. Using data from a randomized controlled trial, we examined whether fathers with poorer emotion regulation would differentially benefit from the After Deployment, Adaptive Parenting Tools program, a 14-session group-based parenting intervention. Prior analyses of the intervention demonstrated benefits to observed couple parenting and children's adjustment, but not to fathers’ observed parenting. In this study we examined whether intervention effects on fathers’ observed distress avoidance were moderated by baseline emotion regulation, and whether reduced distress avoidance was associated with improved observed parenting and reduced children's internalizing symptoms. A subset of the full randomized controlled trial sample (181 families with a father who had returned from deployment to war in Iraq or Afghanistan, a nondeployed mother, and a target child aged 4–13) completed measures at baseline, 12-months, and 24-months postbaseline. Results indicated that fathers high in baseline emotion regulation difficulties assigned to the intervention group showed reductions in observed distress avoidance at 12 months compared to controls, which were subsequently associated with improvements in observed parenting practices and reductions in children's internalizing symptoms at 24 months. The results suggest a role for personalizing parenting programs for fathers high in emotion dysregulation.