Fathers also play an important role during pregnancy and the postpartum period, both for the partner and for the child. With changes in society and increasing early involvement in the care of infants, the father-child relationship has become increasingly more important in recent years. There is growing evidence that fathers can also suffer from mental illnesses during their partner’s pregnancy and especially after the birth of a child. As the transition to the role of a father is a major change in a man’s life, the birth of a child can be a life event that contributes to a first time mental illness or triggers a new episode of an already existing illness. For example, birth complications can also traumatize the attendant fathers and result in trauma sequelae. Peripartum anxiety disorders and depression probably affect approximately 5% of all men and can among other things have a negative impact on the development of exposed children. Specific screening or even treatment services for affected men are still very rare and little research has been performed. Much less is known about the prevalence, risk factors, and treatment of other mental illnesses in fathers, and there is still a great need for research in this respect.