A significant proportion of fathers living with their natural, adopted, step or foster children experience mental illness. Psychiatric illness among fathers can have a devastating impact on children's wellbeing, and even milder forms of paternal mental illness can have serious developmental effects on children. While several pathways linking paternal mental illness with poor child outcomes have been identified, fathers' impaired parenting is an important, potentially malleable factor. Clinicians can assist fathers with mental illness and their families by proactively inquiring about children and by exploring fathering-focused psychological support.